Premium gas

I'm in the regular but top tier gas camp. I always fill up at either Chevron or Shell. I started out with premium for the first year, but the more research I did led me to believe it didn't offer any benefits. I then switched from 91 to 87, and didn't notice one bit of difference with either performance or mpg. I average 12-14 with my mods.

What I do find interesting is this page taken out of a document describing the 2GR-FKS ENGINE. Calls for 91, but I guess they detune Tacomas to use 87 or higher. So imo use 87 unless you are tuned for 91.

 

The US uses a different octane rating system then the rest of the world, the 91 in the manual is equivalent to 87 in the US.

 

The document that was referenced is for a Lexus model that required premium.

 

Interesting...I downloaded that from another thread on here. If anyone has the version of this doc for the Taco engine, please kindly post it. Lot of good info in there...

 

Oh, it is the same exact engine. That's the part a lot of others are unaware of as well. I'll admit I didn't know up until about a year and a half ago or so.

 

So then gets back to my original point. Engine originally designed for 91, except in certain detuned models such as the Tacoma?

 

Basically. The engine has a somewhat high compression ratio, so premium is definitely good for it. But obviously it's not necessary, as can be shown by the taco only requiring 87+.

 

People, the United States, for what ever reason uses a different octane rating system than the rest of the world. The rest of the world uses Research Octane Numbers or RON. The United states uses an average of RON and MON (motor octane number). The number listed in the manual is a RON number, that the US does not list on its gas pumps. The 91listed the is an equivalent to the 87 listed on the pumps. RON numbers are about 5 higher than what the US uses.

 

both are listed kiddo

 

Was referencing the specific page that mike402 has posted, not all manuals ever written.

 

That wasn’t a manual.

http://www.toyotareference.com/guts/tacoma16_engine.pdf

 

Yes it was short one.

 

I tried it once, didn’t notice any meaningful difference. And premium is expensive. My Saab needs premium already, I don’t need to spend more on gas!

 

I have a 2017 Tacoma Sport longbed. I have had from day 1 (Oct 2016) issues with shifting and surging. The Toyota dealers and Corp basically say it is normal. I cannot believe that it is normal so I keep looking for reasons. It has had so many TSBs done to it it is scary. According to Toyota it is up to date on patching.

I have found over the last 2 months that PREMIUM causes the truck to shift nicer and the 40-60 surge is gone. I have alternated between tanks of premium and regular. Every time I go to regular it starts surging and not shifting. Next tank with premium it acts right. So premium definitly is doing something but as usual Toyota says premium would make no difference.

 

Liars ,mine is a 2017 original owner. First 10k mi I used regular did a nice long break in . I've run nothing but premium after 10k mi , now at 180k + miles and still run premium truck loves it. Every now and then I'll run regular to remind myself why I don't use regular gas.

 

The ECU is capable of advancing and retarding timing in response to different octane fuels.

While any benefits may not be very noticeable without a proper tune, there are differences in timing with different octane fuels in these motors. Those who say there is absolutely no difference may have been correct 10+ years ago, but not now.

 

Yes, but it can take a tank or two of fuel for the ECU to fully adjust and benefit the octane Change.

Most people just put 3/4 of a tank, or so of 91, don't notice a difference and then tell everyone "it's bullshit, it doesn't do anything"...

 

yep, takes a lot longer then people think. hell my truck pings on 87 or 89 with any significant load.

 

The 4 cylinder isn’t getting any faster.

 

I don't actually notice any knocking with 87 down here on the gulf coast (if that matters) but i do get a few more miles per tank on 93 after the ECU adjusts.

I did the math a while back and it doesn't save me any money. The extended miles does help on long trips though.