Andre The Giant

Interesting results.

Cosmo Kramer

Mostly a knock against the retailers who market premium fuel to cars that are designed for regular. As for the guy saying that cars designed for premium can run regular due to advanced engine management, if you want the knock sensors to dial back the timing on your uber expensive sports car to save a few bucks a tank, go for it!

I know the new Ecoboost Fords adapt to octane but it takes time for that to happen (not sure about the Chevy Cruise they used). When they dumped premium in on the dyno, the car was still running on its map it created for regular so of course it will run worse.

bureau13

Agreed...the premium gas people of course want everyone to use it, but the auto manufacturers are a better reference for what your car needs.

Btw, all 928s posting on this thread so far should definitely use premium, as they don't have knock sensors

bureau13

Oops, not true...I was looking at the old sig and saw an '85, but missed the S4 above....oops!

mark kibort

ive been using regular for my BMW, chevy tahoe for 14 years now, with no issues and 150,000miles.
however, i do run 91 pump gas on the 928 race car.... never race gas.

bureau13

C'mon Mark...you have to FULLY COMMIT. Don't half-*** this stuff!

mark kibort

I just watched the video.... Did all these people go to STUPID SCHOOL?
I got so excited when they went to the dyno to check hp.. turns out they check HP needed to run the car at 50mph on the rollers. WOW, it took the same hp to run the same speed, and the torque didnt change.. what a surprise.
man.. i was really hoping for a real dyno test!

mark kibort

i love the guy at 10:00..... 91 89 87... = "91% clean, 89% clean, 87% clean" Bahhhhhhh!

Andre The Giant

Yes that was sooooooooooooooo funny !

mark kibort

Carol Montol oil industry expert... 17:00............. what a moron as well. the results of the tests were that the premium in the regular car, ran dirtier.. more hydrocarbons, but he says over time, the premium will make the engine run cleaner and put less diposits in parts of your engine.... (dirty) valves, cylinders, etc. there are so many idiots out there, at ALL the ranks of the oil and car industry. I think the gas station attendant that deciphers the octane numbers as being "% clean" is smarter . that was really funny!

jwyatt8171

Run 93 octane in the 928.
Ran 87 octane in my 2003 Avalanche, that I sold at 298k miles. Only issue fuel related issue I had was fuel pump at 270k.
Running 87 in my F150 Ecoboost(baby engine 2.7). I do see a slight increase in MPG when running higher octane, but not enough to warrant the extra cost.
The testing in this video are about as accurate as my claims here. 1 sample/opinion. I dont think it proves anything.

mark kibort

commom sense should prove it .. why would you get beter gas mileage with higher octane??.. with no changes to the engine, generally if its not knocking with regular, putting premium in the car will only reduce power (unless you make some tuning changes). the video proves a lot. there is no benefit to using premium unless your car doesnt have knock sensors , youre racing a high performance car or is a car that is not high performance, or being used in a high performance fashion.
you run 93 in the 928, why, when i run a 11:3:1, 6.4 liter engine at the track with 91octane with no issues in a myriad of conditions (temp, pressure, performance)
and, if the used a "real" dyno with that econo car , im sure the HP would have been equal or lower with the higher octane gas

jwyatt8171

Are you running stock maps with that setup, or has it been tuned for 91 octane?

mark kibort

completely stock maps. nothing modified but the fuel pressure to make the AFRs in the safe range.

Speedtoys

If your Tahoe recommends 91, and you are using 89, and have "no issues", then I would suggest you are limiting the scope of what the issues could be.ee