Octane's effect on my car?

I have a 2001 Pontiac Grand Am SE Coupe. Not sure if that matters much. I fill up each time on whatever I can afford. I don%26#039;t know much about cars, but generally speaking, whatever is more expensive is higher quality. I usually use 89, however, when my finances won%26#039;t allow that, I put in 87. Recently, I used 91 for the first time in the two months of owning my car. I%26#039;ve noticed my car is the most fuel efficient on 89, and it%26#039;s been burning the 91 like crazy. The 87 doesn%26#039;t go too fast, but it does go faster than the 89. I was told tonight by a friend who knows a few things about cars that I need to stick with whatever I usually put in the car, otherwise I have a higher chance of my fuel pump/filters being damaged. Is this true? And if so, does it mater that I%26#039;ve been putting in 89? What if the previous owners all put 87 in? Am I damaging my car by not following suit?

Octane%26#039;s effect on my car?

OK , Here is the deal... If you are putting higher octane rated fuel in your car and it don%26#039;t need it .. all you are doing is wasting the extra $.10-$.15 per gallon. If your car needs premium grade fuel (which I don%26#039;t believe yours does) then you can run the risk of pre-ignition (ping) and that is not good.

It DOES NOT hurt the engine to run premium in it if it doesn%26#039;t need it.. just your wallet.

Octane is the calculation of the rate by which the fuel burns under compression. Fuel with a higher octane rate burns more complete and cleaner than lower octane rated fuels,but only in an engine where that higher rated fuel is needed..

Most of the older cars (1955-1972) had higher compression ratio engines (10.5/1) and needed higher octane to take advantage of the high compression with the timeing set where it belonged.

Late model vehicles, especially through the 80%26#039;s had very low compression ratios (8.0/1) in some cases in an attempt to run higher igniton timing and smog control to keep down pollution out the tailpipe.. Therefore high octane was not needed so they also started removing the lead from the fuel which also lowered the octane...(I think unleaded started about 1973 along with catalytic convertors).

Anyhow, Your vehicle will run seemingly smoother on higher octane only because it is burning more complete.. The octane rating will have no effect on the fuel filter or the pump.

Hope this helps to clear the air somewhat.

Octane%26#039;s effect on my car?

They have 8 legs, one eye %26amp; don%26#039;t effect your car.

Octane%26#039;s effect on my car?

Use what is recommended for the car. If it takes regular putting in premium won%26#039;t be necessarily better for the car. It just cost you more and has potential to harm the car as it was not made for it.

Octane%26#039;s effect on my car?

i have a 04 grand am and i always put in 87. and yes sorry to say u r damaging ur car. u have to stick to one type. i guess if u tried switching once or twice is fine but if u change it up everytime u fill up ur doing damage. it should tell u on the cap what grade to use mine says 87 so idk. goodluck maybe if ur lucky it didnt do nething

Octane%26#039;s effect on my car?

look in your manual. if 87 is recommended then you are wasting your money on higher octane. however, if 89 is recommended and you are broke and filling up with 87, that%26#039;s not good for your engine and eventually will knock and ping.

use the proper grade octane

Octane%26#039;s effect on my car?

Your friend doesn%26#039;t know what he is talking about. You can switch up gasoline without damaging your pump and filters.

There isn%26#039;t a lot of actual octane in gasoline... you are talking about an octane rating. Gasoline with a higher octane rating can reduce or eliminate engine knocking. Usually high performance engines require premium gasoline to perform properly. Your car would probably do fine with 87 gas. Also it does not determine fuel efficiency. Your driving habits, like how quickly you accelerate and drive on the freeway does have an impact on your fuel efficiency though.

Octane%26#039;s effect on my car?

don%26#039;t worry about octane unless you drive a race car. But do change up brand of fuels every month or so because different companies use different detergents in their fuel. So that way no specific build up, of any deposit left behind by one specific brand can occur. And by the way, I find that filling up on low grade and using STP 3n1 fuel treatment gives me the best performance/mileage and is cheaper and better than filling up on high grade.