92 Octane

Has anyone noticed any difference in MPG or HP running 92 Octane? I was thinking about trying 92 while towing our travel trailer over a Mountain pass.

Thanks!
Brian

 

I got slightly better mpg with premium. It also eliminated the pinging when going up hills before it downshifted.

 

I switched from 87 to 93 for a bit. The biggest difference I noticed was on highway performance. Much better ability to hold gears and power through small inclines.

MPG difference was negligible, and there's so many other factors to account for anyway.

 

I heard it's not supposed to (from Salesman), but I'm pretty sure mine runs much better on premium. I've only tried it on 2 tanks out of 5,500 miles, worth a shot to try!

 

Yes. Not cost effective, but I enjoyed the slight performance gain, whether it was a placebo or not.

 

I did the same while towing 3500+ lbs. Started a half tank before and then filled up before leaving. A little more grunt according to my butt dyno.

 

There is no additional power in higher octane, that's a fact. At higher altitudes it's even less necessary.

 

Run you vehicle on the octane it’s meant to be run. Higher octane fuel is slower burning, which is why the pinging, and few other things mentioned here go away. But running higher octane fuel can also cause premature buildup of carbon on valves and pistons if you vehicle is meant to run on lower octane lime 87.

 

In for the quasi-scientific-domesticated-posting from his wife’s knitting room-bro science. About the fuel for a Japanese pickup truck.

 

My truck runs significantly better on 90 (best we get in Alaska) vs 87. Throttle response from a stop is better, shifting is less wonky, and transitional throttle response in particular is much better, and it drives much better both around town and in the hills on the highway. I get 1.5-2mpg better in all-city driving and about the same mpg on the highway (where i assume MPG is aero limited more than anything else).

My best guess? The engine has pretty high static compression, and Toyota uses lots of tuning adjustments (ignition timing, cam phasing, fuel timing, and whatever else) to make 87 octane work. Running higher octane of course means you’ll have less ECU wizardry making the engine survive, letting it run cleaner. It takes several tanks of premium to get the full drivability effects in my experience, which makes sense if the ECU is relearning based on knock conditions, etc. Conversely it only takes a tank or three of 87 to lose the gains.

At $3.00 for 87 and $3.25 for 90 the mpg bump more or less covers the cost and the truck drives so much better that it’s worth it for me.

 

The shifting issue is squashed with an MT. Just sayin

 

I tried premium for a few tanks. Didn’t notice a difference in power or mileage. Driving a second gen V6 auto trans.

 

The Costco around here carries 86 and 91. Would 86 be ok since no 87?

 

Assuming you live at high altitude? Then yes 86 will be fine.

Good for you. This is the 3rd gen forum.

 

I run ethanol free 87 and 90 depending where I fill up. I get about 1-2 mpg better than the corn mix ethanol stuff. More BTU’s when there isn’t ethanol in the fuel, so it scientifically makes sense. I started running it a few years ago as I know how even 10% ethanol blends can kill lawn equipment and motorcycles. Worth a few bucks more per fill up to avoid any long term issues.

 

For all the people who claim to be engineers on this forum, why hasn't this myth been cast back to the 7th layer of hell?

 

Has anyone ever tested to see if the ECU is leaving any timing on the table while running the recommended octane? Is that a thing with Toyotas?

I'm coming over from the VW world and I'm used to these discussions (there its about ethanol blends and injector limits) having datalogs to show IATs, timing and knock sensor info.

 

Where's the entertainment with that?

 

I get less pinging with 92 octane. I've never noticed a difference in power or fuel economy. But isn't less pinging a good thing? Is it worth the additional cost of 92 vs 87?

 

Are you high?