What fuel do you use?

[Xxyion]

If we are discussing running 87 octane on vehicles closer to sea level, there will be a difference in performance. There’s a reason why tuners will only tune for 93 (or in my circumstance crappy California 91) or higher.

As OP posted earlier, the higher octane helps with knock resistance, another reason why people prefer running premium gas or E85. I will admit that OPs elevation plays a role in his circumstances, so I will concede to that debate. If there is no benefit in going with a higher octane fuel under his circumstances (I.E. noticeable power difference or minimal fluctuations in knock resistance), then go for it.

Oh there will definetly be a difference in performance at sea level. however based on the manual it looks like Toyota says its safe to run any octane rating (whithin reason). It does not mention that performance would stay the same nor would i expect it to.

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[SupraYYJ]

So here is a bit of interesting information i found. In the Owners Manual for the 2021 Supra. It doesnt specifically say what octane is required or recommended.

Your manual must be different than mine. My manual, and the manual at toyota.com, makes a clear recommendation:

 

[Xxyion]

Your manual must be different than mine. My manual, and the manual at toyota.com, makes a clear recommendation:

I am in the US so i imagine some things might be different. I also got mine off of Toyota.com and it has numbers for Ethanol but not octane.

I did notice that it did say recommend. As far as i'm aware, recommend means you can use either. Required means you HAVE to use whatever octane is labeled on your fuel cap.

 

[Axix23]

I am in the US so i imagine some things might be different. I also got mine off of Toyota.com and it has numbers for Ethanol but not octane.

I did notice that it did say recommend. As far as i'm aware, recommend means you can use either. Required means you HAVE to use whatever octane is labeled on your fuel cap.

i guess everybody should just start to lower octane gas from now on

 

[Xxyion]

lol nah i'mma stick with my 91 haha

 

[painpals]

Eh. Thats literally the same argument my buddy has with shooting corrosive ammo though his AK. To me it just seems like a bad idea if you're trying to keep the car in optimal condition.

 

[Rocksandblues]

In my non scientific experiments with gas mileage and 93 vs 89 gas i showed better fuel economy in a N54 and also a SL550 platforms.
was it worth the extra $$?
Probably not

The OP does not have access to high tier Octane anyway. So kind of moot.

More power to you and running what you want in your car. However, I can't help but think if you were really worried about the environment and the costs associated with additional octane or refinement- A Prius may be better suited to your lifestyle and concerns.

 

[diablo2112]

Gas mileage is indeed the result of a complex system interaction. Many things contribute as others have pointed out. You can see this in various tests of regular vs. premium fuel.

As just one example, Car & Driver did a regular vs. premium test . They found some cars got better on regular, others on premium. The biggest difference they saw was a BMW M5 which got 0.7 mpg better mileage on 91 octane compared to 93. Other cars showed a reverse effect.

Generally, 1) the differences are small, and 2) they vary considerably. With such small effects, it takes lots of data to reveal these trends. All that said, it's a simple fact that premium fuel is both slightly less dense and slightly lower in energy content. In real-world conditions, it would take lots of cars and lots of data to tease out this fact.

And I neglected a key variable in my original post. I did these tests in the winter. High-temperatures can exacerbate engine knock. I intend to repeat my monitoring tests this summer. It may be that in my case, regular case works fine in the winter, while higher grade (89 octane) is needed in the summer. We're fortunate that modern engine ECUs and apps allow easy monitoring of all these parameters, including knock detection.

 

[diablo2112]

People put blinders on when it comes to gas for whatever reason

It's mainly psychology. Being exposed to marketing 24/7/365 has conditioned nearly everyone to think expensive=better. Lots of great research here. Among my favorites is perceptions of wine change depending on the price. You can put cheap wine in an expensive bottle, and most folks will rate it higher, even trained Sommeliers.

 

[Drillerkc74]

i chuckle when people pay 68k canadian for a car and lose sleep over the gas cost. doesnt make sense

 

[Dannyvandelft]

i chuckle when people pay 68k canadian for a car and lose sleep over the gas cost. doesnt make sense

Exactly. It's the dumbest thing ever. 50k+ U.S to buy and then worry about gas cost. Put in what it requires or buy a Corolla that runs on 87 just fine.

 

[Escapist]

93 ftw!

 

[Snorlax27]

A gas thread- a sure fire way of instigating a futile debate

So, in conclusion: put whatever gas makes you sleep better at night. Save the debating for things that actually matter like Coke vs Pepsi, IOS vs Android, or if a pound of bricks falls quicker than a pound of feathers.

 

[Shay]

diablo2112 I want to thank you for your post. Looking at your boost pressure of 29.69 it looks like you are not giving up much performance due to your altitude.

I understand your argument that lower octane actually has more energy than higher octane gas. Obviously a certain level of octane is required for a given engine to produce max horsepower, but I don't believe that a higher octane than is necessary will make additional power or better millage.

I use my car as a daily driver and drive it on a trip of 900 miles about once a month. For daily driving and on trips I use lower octane gas. On days I am driving for fun I run 93. I can afford to spent many times more per gallon than I do, but just cant see the logic in wasting money.

Shay

 

[nibble]

I use 93.

here's why from my experience. I used to own nissan maxima '03 /w manual transmission. great car. had more than 300 hp and /w manual I used to burn the tires like no tomorrow. But didn't take care too much and used regular (87) all the time. A bit less power and a bit less fuel economy but I thought it was worth the saving from fuel price. still burns the tire. however, after using regular for 2 years (about 35k miles), under the load, car started to develop knocking. on higher RPM was ok but on a lower RPM and uphill on 3rd gear on 30 or so MPH, I could clearly hear knocking which wasn't happening before even with regular gas. I assume higher volatile fuel like 87 was causing the issue by using over the long period of time. Perhaps you may not experience this in automatic. - car may shift gear to lower gear automatically. So in my opinion, using 87 for once or twice just to get to next station that has 91 or 93 would be ok but using it primarily and prolonged time, will damage the engine. Also, unless you have 100 octane tuned map, using 100 octane would be senseless.

So my advise is use 91 or above if you plan to keep it for long time. But if you are using 87 and plan to sell it, please let next buyer/owner know that you've been using 87.

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