Premium versus Regular

Tom and Ray

What do you think?

Is premium a ploy designed to add to Big Oil coffers? Or, do you think it's a "must" for all high-compression engines, no matter what we said?

Want to chime in with a second opinion on something else we said? (It wouldn't be the first time. But you probably already know that.)

Tell us what you think -- and thanks for joining the discussion!

Tom and Ray

shadowfax

Easy to see for yourself sirs. Go get a high-compression car that says "premium gas only," and fill it with 87 octane. Watch your power go through the floor as the ECU desperately retards the timing to keep the engine from tearing itself up ;)
Or get an older one without a computer that does that and listen to the pinging coming from under the hood ;)

Is it a must in a modern high-compression car? No, I suppose not, as long as you're OK with significant power loss as a result. Myself, if I just spent all that money for a whoop-de-do go fast car, I don't want to be artificially slowing it down by putting lower grade gas in it.

And this is a good time for someone to insert the standard sermon: Higher octane gas does not = higher horsepower. If your car is designed for regular, putting premium in won't turn it into a race car. Premium only has an effect on your power when you're using it to prevent the computer from reducing power to avoid engine knock.

Joseph_E_Meehan

Well premium is a ploy my the oil marketing companies. Even the name "premium" is part of the game.

They infer, in every way possible that "premium" is "better" than regular. However premium in a car that does not need it is at best a waste of money. How many times have you seen tthe adds that infer that premium has more power or will give better mileage (in all gasoline cars) than regular?

Premium is the right choice for those cars that need it or can take advantage of it, but it is a total waste of money for all the rest of the cars on the road.

Joseph_E_Meehan

"premium gas only," ..the ECU desperately retards the timing

I don't believe that the cars specifying premium only have the retard timing feature, only those that "recommend" it do that.

vincec

ive had some vehicles that wouldnt run right on anything less and some that only run right on reg,depends on the vehicle.so their is a difference.

Kendahl

It all depends on the car. Read the owner's manual to find out what you should use.

If the manual specifies premium only, don't use anything less. (In an emergency, you can put in a little bit of regular just to get to the nearest station that sells premium.)

If the manual recommends premium, but says you can use regular, too, you will find that performance, including gas mileage, is better with premium. It may be enough to wipe out the price difference between premium and regular.

If the manual specifies regular, using premium won't do any harm, but the car won't perform any better on it than it does on regular. Here, using premium is completely a waste of money.

Unknown

The reason many cars use premium is for higher performance. Putting regular in a car that calls for premium is the wrong answer. You may damage the engine and will certainly loose performance.
The right answer to save money is to look for a car that runs on regular like a Honda Fit our most non-performance oriented cars.

mlouie

My pet peeve is that the octane level of regular, mid and premium varies from state to state. My owner's manual says to use 86 octane gas. In Colorado where I live, regular is 85 so I have to buy mid-grade which is 87. In Michigan, where I grew up, Regular is 86 so I could use regular if I lived there. Why is there this disparity between different states? That's what I would like to know.

Unknown

Dear Sir, ALL cars built for sale in the U.S. Have had some form of "ignition retard" and have since the 1990's. Some as early as the early 1980's. (Even Chrysler K-Cars!) Check it out!

Joseph_E_Meehan

Don't forget that there are two methods of measuring octane and they don't give the same numbers. Generally in the US the posted number is the simple average of the two methods.

Unknown

O.K. Start by takeing any basic automotive engine course and pay a lot of attention to the parts that talk about compression, power, timing advace, and detonation. Then try rewriting this little fable of ypurs.