i was planning to get a tl or prelude and i know they say they require to have premium fuel in it, but i did some research and came across two sites about regular fuel vs premium.
Premium vs. Regular | Car Talk

6 Myths About Gas Mileage - CBS News

dont know if what they are saying is accurate, so thats why i posted here to get your opinions.
btw im only using my car as transportation for school and short distance drives

 

If the engineers that designed the higher compression engine and say you eed higher octane fuel to avoid detonation, and you end up ruining your engine to save 10 cents a gallon on an expensive car, it will be your loss.

 

It doesn't work. If there's no damage, that's because the computer has cut the ignition timing back to prevent knocking. That will reduce your mpg enough that it would have been cheaper overall to buy premium in the first place.

When operating cost is important, select a car that is specified for regular gas and gets good mpg.

 

ok thanks for clarifying about this, make a lot more sense

 

The truth of these myths only apply to cars that are designed to run on regular-grade gasoline (87 octane). If the auto manufacturer says use 91+, use 91+. If it says to use 87, then use 87. The real truth of the myth about premium vs. regular is that the car will not likely see positive results by going higher than the manufacturer-recommended/required octane of fuel. Going lower than that though will definitely achieve negative results (reduced engine performance and/or gas mileage, and potentially engine damage due to misfiring/pre-ignition).


The reason that certain cars require higher grade fuel is usually (if not always) due to their higher engine compression, or put simply: higher pressure in the combustion chamber. This all has to do with cylinder/piston size, stroke, etc. The higher the pressure, or compression, the more likely it is that the fuel in the chamber will "spontaneously" detonate due to this pressure rather than waiting for the spark plugs to ignite it in a controlled sequence/timing. Without the right fuel, the end result is pre-detonation/misfiring.

This is where higher octane fuels come into play. Octane is a measure of a fuel's resistance to burn. The high octane fuel is more resistant to burn, and thus more resistant to the high engine compression, and when a high enough octane is used the fuel will not pre-detonate/cause misfiring. This allows the spark plugs to do their job and ignite the fuel in a controlled manner, resulting in a properly running engine.

 

^knowledge

 

Premium has a higher octane rating, it burns longer. If you plan on driving at a constant 70mph for a long time, use premium to get a small bump in economy. For around town, you won't get any better so stick to regular UNLESS your car requires premium.

 

Misinformation. Premium and regular burn at the same speed. The difference is that lower octane is less stable and more prone to knocking/detonation under the higher cylinder pressure of a higher compression engine.

Premium doesn't have a higher resistance to burning, it has a higher resistance to ignite. When people who know what they are talking about say it has a higher resistance to burn, they mean it has a higher resistance to start burning/ignite (such as under the pressure of a high compression engine, or with advanced timing), not that it burns slower once ignited.

The only part of your post that is correct is that you don't need premium unless your car requires premium [to prevent engine knocking]. But this applies always, even on highway. In fact, you're actually more prone to knocking while accelerating, not cruising.

 

Thanks for setting it straight, trustdestruction. Bottom line: go with the fuel grade your engine was designed to handle, no less, unless you are willing to pay for damages that can get expensive.

 

It won't hurt to purchase a higher than recommended grade either so I recommend trying the minimum that your car can handle for say 3 tanks and see what your mpg's average out to. Then try premium for 3 tanks straight and see what your mpg's average out to. I had an old dodge ram that got me a constant 8mpg on regular and 11mpg on premium, it was enough to warrant purchasing premium.