Is there really a huge difference in in the fuel grades for my cars ?

Answer 1

Yes. The octane measures gasolines ability to resist knock. If you have a high compression or forced induction engine high heat and spark knock can destroy pistons. This is why performance cars recommend better gasoline. The engines do have knock sensors which automatically retard spark timing to protect itself. Better gas can run more advanced timing without knocking and will produce more power per mile, increasing fuel economy. On a normal engine it isnt enough to justify the price difference.

I'll let you in a little secret though. Most gas stations have three tanks. Two with regular unleaded and one with premium. The second regular is a reserve. The pumps mix the premium and regular to give mid grade. Sneaky.

If your car is high performance run the better gas but regular oil changes will keep an engine going longer.

Answer 2

No one has mentioned anything about detergency or volatility. Not all regular fuels are the same.. There is such a thing as a "tier one" fuel, which has tested out to burn more efficiently and keep things clean. BMW tests all fuels annually and publishes a report on fuels and fuel burning in a little pamphlet that has photo-micrographs of the build-up of carbon and deposits made(or not made) by each popular fuel manufacturer. Mobil, Exxon and Chevron have consistently proven to "burn the best"

Answer 3

All gasolines vary according to geography to account for season, altitude and environmental regulation. Regular and Premium vary in octane, higher octane allows it to function in higher compression engines, but it costs more to make and sells at a higher price. If you don't need the octane then you are wasting money to buy it.
Other difference is that premium sometimes has more additives that might keep your engine cleaner, but you can buy the same stuff cheaper and use it occasionally if needed.
Mileage and power are the same for all grades except for ethanol mixes which will have about 4% lower mileage.
Also most oil companies trade gasoline in certain markets so there is no guarantee that the gasoline you buy was made by the seller.

EDIT, for Robert M: Volatility is set by legislation with maximum values set according to season. Higher volatility gas is cheaper to make so all blenders hit the legislated number bang on.
Detergents are one of the many additives including anti-static, lubricity, corrosion inhibitor amongst others.

Answer 4

hi I once spoke to a guy that said he owned Mobil gas stations, and he said there is not a big difference, between 93 high test and 87 test. I have personally tried it in my car 15 yrs ago and my engine made less noise and ran better on high test fuel. The guy i spoke to said sometimes its hard to test the fuel when it gets delivered from the ports. And some dishonest gas station owners put regular in the middle grade and the middle grade in the high test. hope I answered something here.

Answer 5

Well I get about 3 mpg more to the gallon with premium over regular unleaded in my Landrover. If I use regular I can literally watch the fuel needle drop as I drive. But not with premium

Answer 6

most cars made in the last 20 years were made to run on regular unleaded. if you added any performance parts or chips, then you might do better with better gas. other wise, use the regular stuff and save your money. you probally won't notice any difference with different grades of gas.

Answer 7

it depends what kind of car u have , some cars need premium or mid grade , though most cars run on 87 regular , check ur cars owners manual to see which gas is best for ur car

Answer 8

It depends on your car. Some of the Sporty/Luxury cars don't run well on lower grades.

Answer 9

my truck craves 91octane gas i do feel a power loss if i use lower octanes

Answer 10

yes thier is they are controlled read a pump then contact source using gathered info.