Higher MPG with Premium gas?

May be a fluke... butttttt... depending on where you are at, is it possible the shift from winter to summer gas and temps just happened for you? I have always gotten about an 8 to 10 percent hit on my mgp during winter, and then right back up during summer. It was 40's and 50's for us until like a week or two ago, now it's ~80 the last three days.

 

A 35% reduction (check your math) in the energy content of 10% of the fuel is about 3.5% overall.

So about the same difference as the change in diameter when going from 265/70/16 to 265/75/16 tires, except in the other direction.

So, the performance hit from bigger tires is potentially offset by using premium (ethanol free) fuel.
Is that worth 10-15 bucks per fill-up? Maybe......

 

Same here, paid 4.59 for gas at Costco the other day. Not premium.

 

I run 93 in my 2022 Tacoma and my 2011 Camry. It's got to be better because it costs more.

 

^The #1 reason it sells.
Well, that and creative marketing..

All the legitimate reasons are secondary.

 

Basically, you pay more to get more.

 

I've known this about my 2nd gen since I bought it. Most Toyotas benefit from higher octane, they just don't need it.

 

Can confirm better gas milage. Over long sample 2-3 mpg/gallon.

 

I don't think I get better gas mileage with 93, but I certainly get a lot less (i.e. no) spark knock with it.

 

I had my staff run the numbers; it ain't worth it!

 

If you have a tune built for octane learning, then yes you can get better MPGs.
I have a KDMax tune and I see a noticeable difference between 87 and 91 in both power and mileage, especially on warm days where the engine will pull timing to avoid knock on 87 octane.

Stock tune I didn't notice squat when I tried both

 

Yea, I fat fingered that. 10 percent ethanol gas would have 96.5 percent of the energy density. Less than 1 mpg at the mileage these trucks get. Mileage increases and decreases are better explained by variability in the quality of pump gas and seasonal or temperature changes.

 

Definitely the first time this has been discussed

 

Not saying anyone’s right or wrong but gudalsson is usually right. From what I’ve seen

 

On 90 octane non ethanol premium, winter 20mpg, summer 24mpg.In my humble opinion ethanol mixed in with gas is irrelevant....just like cutting cylinder's off in a v8 it doesnt do a thing for the good in any engine.

 

Despite having a solid understanding of 4-stroke engines, compression and octane; I went ahead and ran 3 back to back tanks of 93 in my truck and noted no difference other than costing about $20 more per fill-up. I suppose tried it in order to definitively prove to myself that adding octane to a platform that doesn't require it serves no benefit.

I use an app to log maintenance and it also tracks each fill-up which calculates the MPG.

 

I didn't fill up the tank yesterday, wife has an eye exam requires dilation, I drove her to work. I'm gonna fill her Lexus ES350 had the same gas from the same station see if there's any difference on the MPG between 87 and 91. Her car always gets 87, 26-27mpg.

 

87 adequate for acceptable MPGs.

 

I’m not concerned about mpg I’m more apprehensive about what 87 octane is doing to the valves. Using low-quality fuel, especially fuel with a low octane rating for a 2gr-fks high-compression engine 11.8:1, can contribute to pre-ignition potentially leading to burnt valves.

 

Exactly. I use 91 for the performance increase. If it gets me better mpg, that's just a bonus.