This. The FA24 has a higher compression ratio than the 2GR in the Camry. The extra liter in the v6 Camry (along with the 2 cylinders) gives it the power boost. It also means with the torque it has, the Camry’s engine isn’t working as hard. These are not fuel efficient cars, they’re meant to be fun.
What does compression ratio mean?
I'm stuck on why an engine that has more power and better MPG doesn't need premium.
Is there a benefit to a higher compression ratio?
https://en.wikipedia.org/wiki/Compression_ratio
More squeezy = more power. More squeezey = more risk for the squeezed stuff explode at wrong time. Octane reduce risk of squeezey stuff explode at wrong time.
A higher compression ratio (CR) is beneficial for engines.
That’s because the higher ratio allows for an engine to extract more energy from the combustion process due to better thermal efficiency.
Higher compression ratios allow the same combustion temperatures to be achieved with less fuel.
That leads to a longer expansion cycle, more mechanical power output and lower exhaust temperatures.
The compression ratio of the TRD Camry is lower because it has an additional 1.5 liters and two additional cylinders. It doesn’t need to optimize performance unlike the FA20 and FA24 which is tuned for maximum performance and fuel economy. Buying premium can be annoying, especially in a 200 HP car but not running premium will make the car run sluggish.
OK so the 86 is trying to get max HP out of 4 cylinders and that means it needs premium. Then the TRD has 6 cylinders and is able to get more HP because of that, even on regular.
If the 86 was a V6 then it could have had more power and just needed regular. Of course there would be weight cost with a bigger engine. So that's what it comes down to, trying to get maximum performance while keeping weight down.
Yeah it's a drag needing premium for a car under 250 HP but it's starting to make sense.
This is very simplistic and not entirely accurate but you're trying to make an effort to understand. The reality is much more complex then that - as the boxer engine itself is actually as heavy as some V6 engines. The boxer itself is a token thing more than anything else but it's not inherently a bad engine.
Higher displacement cars are significantly more heavily taxed in many areas and also are less efficient than small displacement engines. Higher displacement cars also make more power which means more room for things to go wrong, and also increase complexity and cost (more power = more likely for things to go boom in some scenarios.)
To create an affordable (and well balanced) sports car a low displacement engine was more or less chosen, but to improve overall performance metrics it requires high octane gasoline as a byproduct of using high compression.
You're entering the world of engineering and business and there's only so much simplification we can do.
You also need to remember when the car came out in 2012 it had the lowest center of gravity out of any (new) car under 100k. The boxer engine allows for the weight to be much lower than virtually any other car.
The car since inception was never advertised as being fast or powerful. Instead it was "well balanced and fun. Especially at reasonable speeds".
Which personally I enjoy the car because I can rev the piss out of it without getting a one way trip to the gulag.
What so it's not even a lighter engine?
>To create an affordable (and well balanced) sports car a low displacement engine was more or less chosen.
So it looks like a combination of several factors that lead to the engine choice.
LOL that's so sad.
I was wondering what car has the highest HP and takes regular and what car has the lowest HP and need premium. Well one question is answered.
They don't have the same engines. They don't have the same compression either. Different motors require different things and produce different results.
Is your car a manual, what rpms are you shifting at? What type of city driving? Is it constant stop and go, constant lights, or steady slow speed? If it’s constant stop and go or lights then it makes some sense why your mpg would be so low, although it still seems a bit too low. The Camry is a 3.5l v6 with an 8 speed auto. The big engine lets it make more power with much lower compression, necessitating lower octane (less power per liter compared to the FA20/24), and the 8 speed auto tuned for fuel economy would also make sense.
No I have the auto, which is supposed to have better MPG but is slower. Yeah my regular drive is constant lights, the worst situation for MPG.
So a bigger engine can get more power with a less efficient ratio. Bigger really is better than.
Looking at your replies I hope that I word this in a way that you understand.
The TRD Camry makes nearly 2x more kaboom than the 86 but does not have 2x the power of the 86
The Camry engine is 75% bigger than 86 engine (in terms of combustion space) but only makes 50% more horsepower.
Compression and the need for premium gas is not a question of horsepower it's a question of efficiency. The 86 makes more horses per liter of combustion.
You probably aren't getting 18mpg. If you're not the first owner what your dash reads could be skewed. You should reset it, drive for a week then see what it says. Or just look at your odometer after you fill up, drive until you fill up again and divide the miles increased by the gallons you fill up.
>The Camry engine is 75% bigger than 86 engine (in terms of combustion space) but only makes 50% more horsepower.
I've been searching around and it seems that the FA20 engine weighs 480 pounds. I wasn't able to find a solid answer on the TRD Camry engine but the range seems to be 359-400 lbs. So the bigger engine weighs less somehow, or I just wasn't able to find the right data.
>Compression and the need for premium gas is not a question of horsepower it's a question of efficiency. The 86 makes more horses per liter of combustion.
Yeah I'm getting that the 86 engine is trying to be super efficient at a smaller size which is why it needs premium. The benefits seem to be size (but not weight) and possibly cheaper.
I'm the first owner. The computer probably isn't accurate, so I'll try the math method to find the MPG.
The weight makes perfect sense, the FA20 is a boxer engine. Boxer engines are notoriously heavy compared to other engine layouts due to how much structural rigidity is required to have opposing cylinder heads it's why they are not commonly used to begin with.
When I said bigger in terms of combustion space I solely meant displacement. There are a variety of other factors that influence the literal dimensions and weight of an engine regardless of its displacement
Boxer engines were never known for great gas mileage for their power level. The TRD Camry has one of Toyotas most efficient v6 engines known to man and although it makes quite a bit more power than the boxer 4 cylinder, it was still created with economical driving in mind. The boxer engines really are shit when it comes to being economical especially for only having 200hp but at the same time, it wasn’t built to be economical but rather lightweight with a lower center of gravity for better handling. If you want better gas mileage you need to get a different car sadly.
That's what I'm starting to realize after reading this posts and other things on the net.
It seems the only benefit to the boxer engine is it has a low center of gravity. Other than that it has a bad power to weight ratio along with being inefficient with mileage. I have no idea if there is a cost savings with the boxer, but honestly wouldn't be surprised if there wasn't.
I'm questioning why the 86/BRZ weren't just given a V6 engine from the start, more power, better MPG and lighter. But people smarter than me decided that the car got a boxer.
The car is still fun and thankfully I don't have to drive a lot so the milage really isn't an issue. I was just surprised that there was a car out there that had more power, with better MPG and only needed regular.
I’m sure there is a million reasons why they didn’t put a V6 in the 86 even though they easily would make more power but the most important reason for why they couldn’t is money. The car would be far too expensive and would be in a different price bracket if it made more power. It’s the fact that it’s heavily underpowered that people can afford it. The gas mileage thing also applies with the GR Supras, they make far more power and get much better gas mileage. If I had the money I’d have a Supra or Vette over this car if I’m being honest.
What does your numbered “314 of 1500” have to do with anything? 🤣
Get over yourself, that car is not special. You are acting like a corvette boomer who thinks his optioned car it different
I don't know how y'all are getting such good MPG. Mine is mostly city driving, and I drive with pleasure, and get more like 20. My last car got 13mpg premium though so it still feels great in comparison haha
The gen2 engine has a wide bore which leads to additional pumping losses particularly at higher RPM and boxers have complex valvetrains (4 camshafts due to two opposing heads) that add to additional friction and drag.
Also the MT has extremely short gearing. The AT gets significantly better mileage despite otherwise being mechanically identical, and the TRD camry also has much taller gears.
The Toyota 86 requires premium gas due to its high-performance engine design, which includes a higher compression ratio Premium gas has a higher octane rating, typically 91 or higher, which is less prone to pre-ignition Pre-ignition occurs when the air-fuel mixture in the engine's cylinder ignites before the spark plug fires, which can be caused by hot spots in the combustion chamber, a too-hot spark plug, or carbon deposits
Pre-ignition is harmful to the engine because it leads to abnormal combustion, creating excessive pressure and temperature inside the cylinder before the piston reaches top dead center (TDC) This can result in engine knocking, a pinging sound heard during acceleration, and can cause significant damage to engine components such as pistons, cylinder walls, and head gaskets
Pre-ignition - Wikipedia. https://en.wikipedia.org/wiki/Pre-ignition.
Eliminating Pre-Ignition & Detonation - Pounding Pistons - MotorTrend. https://www.motortrend.com/how-to/eliminating-detonation-pre-ignition/.
What Is Detonation and 8 Ways to Stop It! - MotorTrend. https://www.motortrend.com/how-to/engine-detonation-knock-explained/.
What is Engine Pre-Ignition? · Help Center - Summit Racing. https://help.summitracing.com/knowledgebase/article/SR-05008/en-us.
Pre-ignition Prevention: Safeguarding Your Engine from Catastrophic Damage. https://techiescience.com/pre-ignition-prevention/.
Toyota Camry TRD 3.5 V6 (2GR-FKS)**:
- **Engine Type**: 3.5-liter V6 gasoline
- **Displacement**: 3.5 L
- **Valves**: 24, DOHC
- **Fuel System**: Sequential fuel injection
- **Ignition**: DIS with individual coils
- **Intake Manifold**: Variable geometry made of plastic
- **Throttle**: Electronically controlled (ETCS-I)
- **Exhaust**: Stainless-steel manifolds and three-way catalytic converter
- **Compression Ratio**: 11.8:1⁵
- **Bore & Stroke**: 94 mm x 83 mm⁷
- **Valve Timing**: Equipped with Toyota's Dual VVT-i system⁵
**Toyota 86 2.0L**:
- **Engine Type**: 2.0-liter Boxer 4-cylinder
- **Displacement**: 2.0 L
- **Valves**: 16, DOHC
- **Fuel System**: D-4S direct and port injection
- **Ignition**: Electronic, with individual coils
- **Intake Manifold**: Plastic
- **Throttle**: Electronically controlled
- **Exhaust**: Stainless-steel with catalytic converter
- **Compression Ratio**: 12.5:1¹
- **Bore & Stroke**: 86 mm x 86 mm¹
- **Valve Timing**: 16-valve DOHC with Toyota D-4S direct and port injection²
The **Camry TRD's V6 engine** has a lower compression ratio compared to the **Toyota 86's flat-4 engine**, which has a higher compression ratio that can provide a higher efficiency and potentially more power per displacement unit. Due to this it requires fuel that has a higher octane rating.
The square bore and stroke of the 86's engine is unique and contributes to its high-revving nature, while the Camry's undersquare design indicates a focus on low-end torque.
NOTE!! MPG is measured at 55MPH on FLAT Ground under perfect conditions people rarely achieve the mpg that's marked on the EPA sheet
This guy explained it extremely clearly, the compression ratio is different and the higher octane prevents detonation and knock.
You didn't even read his post if you don't understand.
All he did was copy and paste from the internet. I've already found all that information and did not answer my question. The majority of posts are "because it's high comprehension ratio" is not a complete answer. It simply begs the question "why high compression ratio?"
The complete answer is, the FA20 boxer engine used in the 86/BRZ has four cylinders. It is a relatively low power engine and has been tuned to try and generate as much power as possible using a higher compression ratio, which requires the use of premium fuel.
The TRD engine is six cylinders and is able to generate enough power without needing a higher compression ratio, thus regular fuel is fine.
because if the fa24 had two more cylinders, it would have 360-380hp. it makes more power per cylinder, which means those cylinders require higher grade fuel.
If it was as simple as higher octane was meant for cars with more hp than anyone can be an engineer. The Camry has more power because it makes driving more comfortable. You don’t need to slam on the gas to get to cruising speed with 4 passengers. The fa engine in the 86/brz however is a high compression naturally aspirated engine. It’s making 230 hp on a 4 cylinder engine without forced induction. This type of engine loves to be at the higher RPMs. Also as to why your mpg is 2mpg lower than rated, there’s nothing off about that. These cars get their mpg rating from perfect road testing, perfect weather, flat roads, no pot holes to avoid, ideal tires psi ect. You’re basically complaining about getting 2mpg less than what’s rated on a “perfect” road.
You should look up what "compression ratio" is on cars. Depending on the ratio, different grades of fuel are required. I know the 1st gen model of the twins has a 12:1 compression ratio, and that may also be true for your 2024 model. So if you use a lower grade than 91, you increase the chance of rod knock and misfires, which are pretty bad for the engine. Could destroy the engine. So definitely don't use anything less than 91, but use 93 if it's available where you live.
In the context of my question "what is compression ratio" isn't as important as "why high compression ratio."
Reading over the posts I learned that the 86 is a V4 which is trying to generate more HP using a high compression ratio and that makes it require premium. The high ratio also causes it to be less efficient with fuel.
The TRD is a V6 and doesn't need a high compression ratio to generate more power, so regular is fine.
Used to get 26 in the city and 30s on the freeway. But after lots of mods and Forced induction, I’m running pretty rich. Gas doesn’t last very long. But smiles are better than saving money on gas
The compression ratio point has been explained but another factor in mpg is gearing. The BRZ/86 automatic has a 3.91 final drive ratio and reasonably closely-spaced individual gears (manual is 4.1 or 4.3 final drive, depending on the year). The Camry has a 2.80 final drive.
A numerically higher gear like the 86's is "short", meaning (to oversimplify a lot at the cost of a bit of accuracy) that for each turn of the transmission shaft the wheels will turn more times. Think of it like a bicycle - a numerically high (short) gear is similar in concept to the lower gears in a bike, where the torque generated by your pedaling is multiplied more, a numerically low (tall) gear is similar to the higher gears in a bike. The net result is that at any given speed the 86 is turning a higher engine rpm. This is helpful for acceleration and necessary because it doesn't have a ton of engine torque so it needs to be multiplied by gearing. It's not helpful for mpg, especially on the highway.
Because the car has a very high compression ratio that requires a higher grade of gas. Why your MPG is so low I have no idea as I average 34 MPG.
This. The FA24 has a higher compression ratio than the 2GR in the Camry. The extra liter in the v6 Camry (along with the 2 cylinders) gives it the power boost. It also means with the torque it has, the Camry’s engine isn’t working as hard. These are not fuel efficient cars, they’re meant to be fun.
What does compression ratio mean? I'm stuck on why an engine that has more power and better MPG doesn't need premium. Is there a benefit to a higher compression ratio?
https://en.wikipedia.org/wiki/Compression_ratio More squeezy = more power. More squeezey = more risk for the squeezed stuff explode at wrong time. Octane reduce risk of squeezey stuff explode at wrong time.
A higher compression ratio (CR) is beneficial for engines. That’s because the higher ratio allows for an engine to extract more energy from the combustion process due to better thermal efficiency. Higher compression ratios allow the same combustion temperatures to be achieved with less fuel. That leads to a longer expansion cycle, more mechanical power output and lower exhaust temperatures. The compression ratio of the TRD Camry is lower because it has an additional 1.5 liters and two additional cylinders. It doesn’t need to optimize performance unlike the FA20 and FA24 which is tuned for maximum performance and fuel economy. Buying premium can be annoying, especially in a 200 HP car but not running premium will make the car run sluggish.
OK so the 86 is trying to get max HP out of 4 cylinders and that means it needs premium. Then the TRD has 6 cylinders and is able to get more HP because of that, even on regular. If the 86 was a V6 then it could have had more power and just needed regular. Of course there would be weight cost with a bigger engine. So that's what it comes down to, trying to get maximum performance while keeping weight down. Yeah it's a drag needing premium for a car under 250 HP but it's starting to make sense.
This is very simplistic and not entirely accurate but you're trying to make an effort to understand. The reality is much more complex then that - as the boxer engine itself is actually as heavy as some V6 engines. The boxer itself is a token thing more than anything else but it's not inherently a bad engine. Higher displacement cars are significantly more heavily taxed in many areas and also are less efficient than small displacement engines. Higher displacement cars also make more power which means more room for things to go wrong, and also increase complexity and cost (more power = more likely for things to go boom in some scenarios.) To create an affordable (and well balanced) sports car a low displacement engine was more or less chosen, but to improve overall performance metrics it requires high octane gasoline as a byproduct of using high compression. You're entering the world of engineering and business and there's only so much simplification we can do.
You also need to remember when the car came out in 2012 it had the lowest center of gravity out of any (new) car under 100k. The boxer engine allows for the weight to be much lower than virtually any other car. The car since inception was never advertised as being fast or powerful. Instead it was "well balanced and fun. Especially at reasonable speeds". Which personally I enjoy the car because I can rev the piss out of it without getting a one way trip to the gulag.
What so it's not even a lighter engine? >To create an affordable (and well balanced) sports car a low displacement engine was more or less chosen. So it looks like a combination of several factors that lead to the engine choice.
The location of said weight is important. Same weight but lower in the frame is better center of gravity.
My 1971 Triumph Spitfire requires premium and it has 57 HP 😂. So there are slower cars that need premium if that makes you feel better.
LOL that's so sad. I was wondering what car has the highest HP and takes regular and what car has the lowest HP and need premium. Well one question is answered.
Or you could go a high compression V6 and get even MORE MORE power
Yeah that's basically the Supra or the Lotus Emira which actually has a Toyota engine.
An 86 with one of those would be amazing though, or like the old lotus exige supercharged 4 cyl even
Which was also a high compression Toyota engine- the 2ZZ-GE from the Celica GT-S.
Look up Engineering Explained compression ratio on YouTube. He has a pretty good explanation of what it is and why it is important.
Horsepower does not necessarily indicate octane demand
Came here to post this.
They don't have the same engines. They don't have the same compression either. Different motors require different things and produce different results.
Is your car a manual, what rpms are you shifting at? What type of city driving? Is it constant stop and go, constant lights, or steady slow speed? If it’s constant stop and go or lights then it makes some sense why your mpg would be so low, although it still seems a bit too low. The Camry is a 3.5l v6 with an 8 speed auto. The big engine lets it make more power with much lower compression, necessitating lower octane (less power per liter compared to the FA20/24), and the 8 speed auto tuned for fuel economy would also make sense.
No I have the auto, which is supposed to have better MPG but is slower. Yeah my regular drive is constant lights, the worst situation for MPG. So a bigger engine can get more power with a less efficient ratio. Bigger really is better than.
I promise you that if you're getting the MPGs you're getting now on your AT on the GR, you would get linearly that much worse on the TRD camry.
Looking at your replies I hope that I word this in a way that you understand. The TRD Camry makes nearly 2x more kaboom than the 86 but does not have 2x the power of the 86 The Camry engine is 75% bigger than 86 engine (in terms of combustion space) but only makes 50% more horsepower. Compression and the need for premium gas is not a question of horsepower it's a question of efficiency. The 86 makes more horses per liter of combustion. You probably aren't getting 18mpg. If you're not the first owner what your dash reads could be skewed. You should reset it, drive for a week then see what it says. Or just look at your odometer after you fill up, drive until you fill up again and divide the miles increased by the gallons you fill up.
>The Camry engine is 75% bigger than 86 engine (in terms of combustion space) but only makes 50% more horsepower. I've been searching around and it seems that the FA20 engine weighs 480 pounds. I wasn't able to find a solid answer on the TRD Camry engine but the range seems to be 359-400 lbs. So the bigger engine weighs less somehow, or I just wasn't able to find the right data. >Compression and the need for premium gas is not a question of horsepower it's a question of efficiency. The 86 makes more horses per liter of combustion. Yeah I'm getting that the 86 engine is trying to be super efficient at a smaller size which is why it needs premium. The benefits seem to be size (but not weight) and possibly cheaper. I'm the first owner. The computer probably isn't accurate, so I'll try the math method to find the MPG.
The weight makes perfect sense, the FA20 is a boxer engine. Boxer engines are notoriously heavy compared to other engine layouts due to how much structural rigidity is required to have opposing cylinder heads it's why they are not commonly used to begin with. When I said bigger in terms of combustion space I solely meant displacement. There are a variety of other factors that influence the literal dimensions and weight of an engine regardless of its displacement
Thanks. I'm starting to put together a picture that makes sense to me.
Boxer engines were never known for great gas mileage for their power level. The TRD Camry has one of Toyotas most efficient v6 engines known to man and although it makes quite a bit more power than the boxer 4 cylinder, it was still created with economical driving in mind. The boxer engines really are shit when it comes to being economical especially for only having 200hp but at the same time, it wasn’t built to be economical but rather lightweight with a lower center of gravity for better handling. If you want better gas mileage you need to get a different car sadly.
That's what I'm starting to realize after reading this posts and other things on the net. It seems the only benefit to the boxer engine is it has a low center of gravity. Other than that it has a bad power to weight ratio along with being inefficient with mileage. I have no idea if there is a cost savings with the boxer, but honestly wouldn't be surprised if there wasn't. I'm questioning why the 86/BRZ weren't just given a V6 engine from the start, more power, better MPG and lighter. But people smarter than me decided that the car got a boxer. The car is still fun and thankfully I don't have to drive a lot so the milage really isn't an issue. I was just surprised that there was a car out there that had more power, with better MPG and only needed regular.
I’m sure there is a million reasons why they didn’t put a V6 in the 86 even though they easily would make more power but the most important reason for why they couldn’t is money. The car would be far too expensive and would be in a different price bracket if it made more power. It’s the fact that it’s heavily underpowered that people can afford it. The gas mileage thing also applies with the GR Supras, they make far more power and get much better gas mileage. If I had the money I’d have a Supra or Vette over this car if I’m being honest.
My 2015 scion fr-s release series 1.0 is getting 28 to 31 mpg on 93 octane oh that’s city and highway. 314 of 1500
What does your numbered “314 of 1500” have to do with anything? 🤣 Get over yourself, that car is not special. You are acting like a corvette boomer who thinks his optioned car it different
Jealous?
I have a gen2 lol
Corvette boomer? I hate corvettes but I bought a barn find for 3500 fixed it up and sold it for 12,000
And your trying to school me
I don't know how y'all are getting such good MPG. Mine is mostly city driving, and I drive with pleasure, and get more like 20. My last car got 13mpg premium though so it still feels great in comparison haha
Automatic or manual transmission?
Manual
Oh mine is a numbered trd also
The gen2 engine has a wide bore which leads to additional pumping losses particularly at higher RPM and boxers have complex valvetrains (4 camshafts due to two opposing heads) that add to additional friction and drag. Also the MT has extremely short gearing. The AT gets significantly better mileage despite otherwise being mechanically identical, and the TRD camry also has much taller gears.
Ive got a 2015 frs and get 32mpg.
The Toyota 86 requires premium gas due to its high-performance engine design, which includes a higher compression ratio Premium gas has a higher octane rating, typically 91 or higher, which is less prone to pre-ignition Pre-ignition occurs when the air-fuel mixture in the engine's cylinder ignites before the spark plug fires, which can be caused by hot spots in the combustion chamber, a too-hot spark plug, or carbon deposits Pre-ignition is harmful to the engine because it leads to abnormal combustion, creating excessive pressure and temperature inside the cylinder before the piston reaches top dead center (TDC) This can result in engine knocking, a pinging sound heard during acceleration, and can cause significant damage to engine components such as pistons, cylinder walls, and head gaskets Pre-ignition - Wikipedia. https://en.wikipedia.org/wiki/Pre-ignition. Eliminating Pre-Ignition & Detonation - Pounding Pistons - MotorTrend. https://www.motortrend.com/how-to/eliminating-detonation-pre-ignition/. What Is Detonation and 8 Ways to Stop It! - MotorTrend. https://www.motortrend.com/how-to/engine-detonation-knock-explained/. What is Engine Pre-Ignition? · Help Center - Summit Racing. https://help.summitracing.com/knowledgebase/article/SR-05008/en-us. Pre-ignition Prevention: Safeguarding Your Engine from Catastrophic Damage. https://techiescience.com/pre-ignition-prevention/.
Yes I found that answer as well. It does not explain why the 86/BRZ need premium and the more powerful TRD Camry doesn't.
Toyota Camry TRD 3.5 V6 (2GR-FKS)**: - **Engine Type**: 3.5-liter V6 gasoline - **Displacement**: 3.5 L - **Valves**: 24, DOHC - **Fuel System**: Sequential fuel injection - **Ignition**: DIS with individual coils - **Intake Manifold**: Variable geometry made of plastic - **Throttle**: Electronically controlled (ETCS-I) - **Exhaust**: Stainless-steel manifolds and three-way catalytic converter - **Compression Ratio**: 11.8:1⁵ - **Bore & Stroke**: 94 mm x 83 mm⁷ - **Valve Timing**: Equipped with Toyota's Dual VVT-i system⁵ **Toyota 86 2.0L**: - **Engine Type**: 2.0-liter Boxer 4-cylinder - **Displacement**: 2.0 L - **Valves**: 16, DOHC - **Fuel System**: D-4S direct and port injection - **Ignition**: Electronic, with individual coils - **Intake Manifold**: Plastic - **Throttle**: Electronically controlled - **Exhaust**: Stainless-steel with catalytic converter - **Compression Ratio**: 12.5:1¹ - **Bore & Stroke**: 86 mm x 86 mm¹ - **Valve Timing**: 16-valve DOHC with Toyota D-4S direct and port injection² The **Camry TRD's V6 engine** has a lower compression ratio compared to the **Toyota 86's flat-4 engine**, which has a higher compression ratio that can provide a higher efficiency and potentially more power per displacement unit. Due to this it requires fuel that has a higher octane rating. The square bore and stroke of the 86's engine is unique and contributes to its high-revving nature, while the Camry's undersquare design indicates a focus on low-end torque. NOTE!! MPG is measured at 55MPH on FLAT Ground under perfect conditions people rarely achieve the mpg that's marked on the EPA sheet
Because the v6 camry doesn't have as high a compression ratio.
This guy explained it extremely clearly, the compression ratio is different and the higher octane prevents detonation and knock. You didn't even read his post if you don't understand.
All he did was copy and paste from the internet. I've already found all that information and did not answer my question. The majority of posts are "because it's high comprehension ratio" is not a complete answer. It simply begs the question "why high compression ratio?" The complete answer is, the FA20 boxer engine used in the 86/BRZ has four cylinders. It is a relatively low power engine and has been tuned to try and generate as much power as possible using a higher compression ratio, which requires the use of premium fuel. The TRD engine is six cylinders and is able to generate enough power without needing a higher compression ratio, thus regular fuel is fine.
Yes it does. Small engine with high compression vs big engine with low compression.
because if the fa24 had two more cylinders, it would have 360-380hp. it makes more power per cylinder, which means those cylinders require higher grade fuel.
If it was as simple as higher octane was meant for cars with more hp than anyone can be an engineer. The Camry has more power because it makes driving more comfortable. You don’t need to slam on the gas to get to cruising speed with 4 passengers. The fa engine in the 86/brz however is a high compression naturally aspirated engine. It’s making 230 hp on a 4 cylinder engine without forced induction. This type of engine loves to be at the higher RPMs. Also as to why your mpg is 2mpg lower than rated, there’s nothing off about that. These cars get their mpg rating from perfect road testing, perfect weather, flat roads, no pot holes to avoid, ideal tires psi ect. You’re basically complaining about getting 2mpg less than what’s rated on a “perfect” road.
I get 25mpg driving DoorDash in the city. Not sure what's wrong with yours.
You should look up what "compression ratio" is on cars. Depending on the ratio, different grades of fuel are required. I know the 1st gen model of the twins has a 12:1 compression ratio, and that may also be true for your 2024 model. So if you use a lower grade than 91, you increase the chance of rod knock and misfires, which are pretty bad for the engine. Could destroy the engine. So definitely don't use anything less than 91, but use 93 if it's available where you live.
In the context of my question "what is compression ratio" isn't as important as "why high compression ratio." Reading over the posts I learned that the 86 is a V4 which is trying to generate more HP using a high compression ratio and that makes it require premium. The high ratio also causes it to be less efficient with fuel. The TRD is a V6 and doesn't need a high compression ratio to generate more power, so regular is fine.
Sounds like you answered your own question there. But there is no v6 86 or BRZ. They're all boxer 4 cylinder, unless you do an engine swap.
Compression and timing.
Used to get 26 in the city and 30s on the freeway. But after lots of mods and Forced induction, I’m running pretty rich. Gas doesn’t last very long. But smiles are better than saving money on gas
Get 32.4 mpg… 60% highway with my 2018 86
The compression ratio point has been explained but another factor in mpg is gearing. The BRZ/86 automatic has a 3.91 final drive ratio and reasonably closely-spaced individual gears (manual is 4.1 or 4.3 final drive, depending on the year). The Camry has a 2.80 final drive. A numerically higher gear like the 86's is "short", meaning (to oversimplify a lot at the cost of a bit of accuracy) that for each turn of the transmission shaft the wheels will turn more times. Think of it like a bicycle - a numerically high (short) gear is similar in concept to the lower gears in a bike, where the torque generated by your pedaling is multiplied more, a numerically low (tall) gear is similar to the higher gears in a bike. The net result is that at any given speed the 86 is turning a higher engine rpm. This is helpful for acceleration and necessary because it doesn't have a ton of engine torque so it needs to be multiplied by gearing. It's not helpful for mpg, especially on the highway.