friend only buys premium gas?

Question

I have a buddy that drives a completely stock 2004 Mitsubishi Lancer who only runs Shell Premium Gas in it. He insists that it gives him better performance and mileage, but its a problem cause whenever we end up riding in his car he asks for a ridiculous amount of gas money.

Ive talked to a couple of mechanics, including my grandpa whos been workin on cars since the 50s, and research on the internet. and its obvious that its not doing a damn thing except over-working his engine. anyone else got some input to add about this?

it is bare bones stock

Answer 1

Your friend is wasting a LOT of money. The computer system of the Lancer adjusts for air/fuel mixtures and is calibrated for regular. Running premium may give a slight mileage advantage as the ECM will recognize a better combustion in the cylinders and adjust accordingly but the cost of premium fuel will cost much more than the nominal (if any) better mileage he may get. Does he run synthetic racing oil in the engine? That would be far better for the engine than premium gas!

Answer 2

If he wants to run expensive gas in his car, let him. I wouldn't give him any money for it though. If the car can run on 87 octane, running 93 octane is doing nothing but costing him more money. The octane does nothing to boost performance. The only thing it does is keep an engine from pinging. His stock Lancer should run on regular unleaded gas without a problem.

Answer 3

It wouldn't overwork the engine, it justs wastes his money.

The way octane works is it retards the combustion of the gasoline. There are two ways to ignite the gasoline in the cylinder: 1) by a spark plug, and 2) by compression ONLY (that's how diesel engines work). Newer engines, in order to produce more power, run on higher compression, and thus increases the chance of the cylinder igniting out of sequence. Thus, you use higher octane gasoline to prevent mis-firing from happening. If you are not running a high compression engine, then there's no reason to use high octane gasoline.

Thus, your friend is not a friend at all.

Answer 4

A couple mechanics told me the same thing but I think it depends on the vehicle you drive. I bought a Pontiac Firebird in 2000 and it HAD to have the premium. Though, I used Amoco. Next, I drove a Toyota Camry that did not make a difference......

Answer 5

premium fuel will make your car run cleaner and give a very slight increase in performance while giving a better fuel economy. So the answer is for better mileage and less pollution use premium

Answer 6

I don't think your buddy buys premium gas for his car ... instead YOU are buying the premium. That is ridiculous.. he is charging you guys so he can buy a better gas.

Premium might keep his fuel injectors a bit cleaner but that is about it.

Your "friend" sounds like a shyster !!!

Answer 7

Unless Mitsubishi recommends a higher grade of gas, he is wasting his money.

Answer 8

your right the higher octane is not doing a think for his car but by putting in a ethanol bled in he is keeping his carbon down in the motor Toyota's are bad about getting carbon it the intakes and ethanol will take care of the problem or prolone before you have to have it serviced but if it is bear bones stock the extra octane is doing nothing.

Answer 9

Your friend may be hurting the engine not getting the benefit ,tell him to read the owners manual!

Answer 10

i did the same thing by using premium gas and found out that my car did not need it and that it was a waste of money. he should check his owner's manual to see what gas it should be using.

him asking for gas money.. kind of makes you want to walk to your destination huh?