Kizashi Club

Another good article to read if you still think premium fuel is better for a car like the Kizzy which only requires 87 octane. To quote from page 2 of the article: "The good news, though, is that if your car isn’t as high-strung, there’s absolutely no advantage to putting a higher-grade fuel than necessary in the tank unless you’re experiencing pinging or knocking.

One persistent misunderstanding about octane ratings is that premium is somehow “cleaner.” Another is that you can get better fuel economy with the pricier stuff. Both of these beliefs are completely false: If your car will run fine on cheap gas, save your money and keep buying 87. Of course, you should never stray from the fuel grade recommended by your owner’s manual, as this could potentially void your warranty." It's amazing how many people either don't believe this info or somehow believe in the magic of premium fuel.


http://www.cheatsheet.com/automobiles/e ... er.html/2/

I know everyone doesn't agree on this subject but somehow I don't remember many articles which state the opposite (use premium fuel for better mpg, etc. in a car rated for 87 octane).

tgrl I guess!

I agree with the article but what's interesting is that WESHOOT2 has noticed better mileage on premium fuel. I personally haven't on the odd times I ran 89 or 92 so YMMV obviously.

I think premium could be technically cleaner if it contains additives that the lower grades don't. I believe Shell offers additional additives in their V-Power premium fuel over their lower grades.
As for the performance benefits of premium, I agree that it's a nominal factor if existent at all for our cars. Even if so, I really don't think it benefits most drivers. Premium or not, my driving conditions don't demand higher performance fuel and therefore I wouldn't benefit from it. I also have an issue with running more costly fuel on what is essentially supposed to be an affordable car designed to burn regular. I'd get premium fuel for a sports car, a luxury car, or turbocharged car, but something like the Kizashi neither offers the performance nor has the technology to justify using premium fuel IMO so I rather not pay for it.

KuroNekko wrote:I think premium could be technically cleaner if it contains additives that the lower grades don't. I believe Shell offers additional additives in their V-Power premium fuel over their lower grades.
As for the performance benefits of premium, I agree that it's a nominal factor if existent at all for our cars. Even if so, I really don't think it benefits most drivers. Premium or not, my driving conditions don't demand higher performance fuel and therefore I wouldn't benefit from it. I also have an issue with running more costly fuel on what is essentially supposed to be an affordable car designed to burn regular. I'd get premium fuel for a sports car, a luxury car, or turbocharged car, but something like the Kizashi neither offers the performance nor has the technology to justify using premium fuel IMO so I rather not pay for it.

Correct. Certain brands of higher octane gasoline contain additional detergents that aid in cleaning. Running a higher octane than required will add no significant performance benefit unless the vehicle's engine can account for it and advance timing. Higher octane gasoline should not technically change gas mileage.

Simply put, run what is specified in the manual.

I agree with this 100%, but the placebo effect is pretty big on "premium" fuel. You can't convince people no matter what.

We must test this then. Occasionally I would run premium gas in my Kizashi for a couple weeks to see mileage changes, but 2-3 weeks is not long enough for solid testing. With gas prices as they are now, I'm considering this, however it is the winter, so idling to warm up takes longer than it would in the summer time and would result in an unfairish comparison. I'll wait until late spring or something if gas prices do not shoot back up.

Ha! I spit on your testing! Ha!

Running premium allows timing changes before knock-reduction takes place. Since much of my driving consists of pedal-matting my car delivers both more power and better mileage.
Tested (in two now); YRMV.

FWIW, I"VE recently been testing middle-grade Mobil, Shell, and Citgo. Testing continues.......

Contrary to what most believe, premium gas is less combustible than lower octane gas. The octane rating is a fuel's resistance to pre-combustion or detonation (some people know it as knocking) higher compression pressures make it easier to ignite the air fuel mix, if left unchecked it will ignite too early, so a fuel with a higher octane rating is needed to resist early combustion. The difference between 87 and 93 is so negligible on NA engines that it really doesn't matter what grade you get. High octane fuel will only be noticeably different if you have boost or high compression.

If your your car is CVT then obviously you wont notice any difference.