I ran 87 one time and the pinging was so bad that i'll never do it again......93 all the way.

 

Thanks for all the info!!

 

Hmmm.....my Tundra 4.7 has 10.2:1 compression and calls for regular unleaded. With that being said, I wouldn't put anything in the car that the owner's manual doesn't call for or you're asking for trouble (unless your car isn't stock and/or has been reprogrammed).

 

I ran that 30 mpg tank of 86 octane while driving across New Mexico in August. I also ran 87 in OK and TX. Never had a bit of problems.

Again, this what while I was much closer to stock. I've talked to guy with cars more modded than mine that run 87 for daily driving, but I don't anymore.

I think its interesting how people think 87 octane is a lesser or dirty fuel because it costs less. It isn't.

 

And it's funny how people think 91+ is "cleaner" because it costs more, so they run it before doing an emissions test, and FAIL on high hydro-carbons because their run-of-the-mill engine doesn't generate enough heat to completely burn the fuel, thus, high volumes of un-burnt fuel (aka: hydro-carbons ) out the exhaust, and voila, a failed test!

That's good marketing for ya .

 

But, mixed 1/4 to 3/8 regular w/ the remainder of super ( top offs ) & never had any trouble.

Blew it off , though, as at 80 cents to a dollar's worth of savings per top off it just was not worth it.


I think on a basically stock machine it would not be a problem so long as you can live w/ the performance loss.


Britt

 

Of course you can feel the difference ... when it prevents the engine from pinging, and the knock sensors from retarding the timing!!

Based on your logic, do you think that the average "grocery getter" with ~9:1 compression or less runs BETTER or cleaner on 91 than it does on 87???? Although, I guess raw fuel may wash the cylinder walls while it's in there????

 

Now we're getting off into two different discussions so I'll clarify

87 and 91 Octane are both very clean fuels so long as you purchase it from a reputable company... "Shell, Chevron, BP, Exxon ect..." I've had bad 87 Octane and I've had bad 91 Octane fuel... The Base fuel itself is whats used to add octane and thus HAS to be clean otherwise both the 87 and 91 will BOTH be dirty regardless of the additives...

91 Octane is generally CONCIEVED to be cleaner than 87 Octane because it usually contains up to five times more additives... However this is mainly to help clean the fuel system, not the fuel itself...

Here I'll clarify it all for you...
87 was truly as dirty as you make it sound there wouldn't be a single Honda running around...


Now for OCTANE - Yes there is a difference between 87 and 91 obviously... Higher compression ratio's will need higher octane... However this has nothing to do with the cleanliness of the fuel...

 

what scares me with the premium fuels is very few people run it, around here anyways. it sits in the tanks longer, thus is older. who knows what octane it really even is by the time it gets to your tank.

 

it probably depends slightly on the towns you live at. i live in a fairly small town and i only know of one person that buys premium. of course there will be others but i don't care for stale gas. that is not saying the regular isn't stale either though.

 

I have ran 87 in my LT1 several times with no loss in performance or anything. The LT1 also has a higher compression ratio than the LS1. I usually do (or did, the sold my car) run premium.

 

Mid-grade is a regular/premium blend. You don't need to only buy premium for it to leave the holding tank....but then again, this thread has taken a huge tangent.

 

Take it to the track and test it out sometime. What a car feels like on the road and what the actual performance loss is are two completely dofferent animals.
Had a guy at the track one time in the middle of summer ask me to scan his car because it was running way slower than he thought it should. I put the scan tool on and his timing was down to 6 degrees at WOT. I asked him what gas he had in there and he said ''regular unleaded''. And he ws at least 4mph down fron where he should have been, that's where I got the 40hp from.

And for those that actually read the owners manual it's say recommended fuel 91 octane. You can use a lower grade but there's a reason that they write it that way. Do you actually think that they would recommend 91 if the motor ran just as good on 87? No because they loose customers with that use premium sticker every day.

 

I would be willing to bet the "shelf" life of gasoline is much higher than it is likely to be in the tanks.

 

Running low octane fuel in our engines as said before is a very bad idea. Audible detonation, a guarantee with 87 octane, is not only destroying your pistons and chambers but it most certainly DOES decrease power output. By the time you can hear the detonation, the PCM has already pulled a ton of timing to prevent it, and thus a power loss. While I can't back up the 40HP loss with hard evidence, I don't doubt it. I've seen just a few degrees of timing here or there make or kill more HP than that. If you really want to run 87 octane, you're driving the wrong car!