Is premium gasoline really better for your car? It's like 20 cents/gallon more than just regular unleaded. If it is better for the car, I"m switching to premium. I drive a 1997 Toyota Camry.

For your car, no, you'd just be wasting your money.

Most cars don't need the 93 octane level. I've driven Camaro's with 8 cylinder engines where most think they need premium gas but according the manufacturer and most mechanics, using higher premium gasoline can hurt your car more than do good.

In most cases, if you use 93 octane instead of the 87 octane, the only thing it does is it will last a little longer as 87 octane combusts at a different rate than 93 or 91 for that matter. You might be spending 20 more cents and your gas might last an extra 60 or so miles than you'd usually get from a normal tank of gas but if you think about it, your not saving any money or miles by such means.

Check your owners manual though as it will tell you what is recommended for your car and engine. If it doesn't, call your car dealership or look it up online. The only car that comes straight to mind that they recommend premium is the Corvette and other cars in it's class.

I have a 2003 Honda S2000, and the manufacturer recommends premium fuel. They also say that you can use almost any grade of fuel, but that you will lose some performance.

I don't know if premium is better, but it is recommended for my automobile.

Like I said, it just all depends on the car. A Toyota Camry though, probably not worth it to pay the extra 20 cents, especially if your only going to get an extra few miles out of it. You'd make up for it the next time you fill up with regular.

I couldn't find a 97 Camry but the 2004's state they recommend 91 octane.

I say unless you have a high compression ratio engine then use regular...

http://www.co.suffolk.ny.us/webtemp3.cfm?dept=3&id=2049

KC

My mercedes also reccomends premium, but it doesn't hurt it, the computer will automatically compensate. I once worked it out that the extra octane made the fuel last long enough so that it ended up costing almost the same amount, I just had to fill up less frequently(not that much less frequently, it's not like you're going to see much difference on an 11 gallon tank.)

Exactly my point, just not in those exact words.

Running high octane fuel will not ruin your engine.
It will not burn piston rings.
It will not overheat the engine.

"High octane" fuel has a higher flash point and burns a little more slowly. It's tailored to be less prone to preignition.

It MIGHT result in some carbon buildup but that's about it.

By the way, if you're running a Camaro with <91 octane fuel and the compression is higher than 10:1, you're slowly ruining the engine. What happens is the engine knocks, the ECM "hears" the knocking via the knock sensor, so it retards the timing - but not before the engine is already pinging. The timing remains retarded for a few milliseconds, then it's advanced again to normal, it begins to knock, so again the ECM pulls the timing back - and each time the engine knocks it's causing damage to the crown of the piston and the valves and valve seats. This damage (normally) occurs over the long term because a few microscopic pits here and there don't immediately reduce performance in noticeable or easily measurable terms, but over the course of a few thousand miles, it becomes very measurable, and a few thousand more suddenly your once-fast LS1-equipped or LT4-equipped Z-28 is now returning <20mpg on the highway and 6+ second 0-60 times, and >14.0 seconds in the quarter - and not a prayer of seeing anything even remotely close 165-170mph if you're fortunate enough to participate in a sanctioned ORR event.

Run high octane fuel in high-compression or turbo/supercharged engines. In your economy car or a truck with a low-compression engine? Run 87 or 86 octane gasoline. You'll also get better fuel economy on high octane fuel with a high performance engine due to the ECM's ability to run the engine with an ideal timing and fuel curve.

B.S.

The computer only compensates AFTER the engine begins to ping. The timing is pulled back a few degrees and the fuel mixture is richened a bit, then after a few milliseconds the timing is re-advanced and the fuel mixture leaned back again, and then the cycle repeats due to using sub-par fuel (for the application). The damage is still being done, the ECM just slows down the damage by cycling it. The ECM only prevents immediate catastrophic damage, not long-term damage to the engine.

Not that I know anything about engines or anything, I'm just really really into Corvettes and first-generation Ford Rustangs, er, Mustangs.

In your case, not really, no.

Did I not say the same thing in one sentence?

KC

I have not read all the other posts so maybe this has been said already but usually No. It depends on your car and engine. High octane gas is for high compression engines, it really does nothing for a small, transportation type car.

I disagree that using lower grade gasoline will hurt most cars or any car for that matter. I have a buddy I've known since we were running around in pampers who is a Certified Lexus mechanic who swears higher octane fuels are pointless in everyday driving. He'd only recommend it is if you like higher performance out of your vehicle with more horsepower, etc. He once mentioned to me longterm usage of higher octane fuels can do more harm than good and the majority of the time it's just the car manufacturers pushing for the premium grade for the cars.

But I drove a 94 Camaro til it reached 130k miles using nothing but 87 octane, never had any problems relating to fuel or the engine. The only reason I traded it in was the A/C was going out, the driver side window stopped rolling down and I didn't feel like putting money into the car any longer. I live in Texas, you need A/C when you live in Texas..

I also owned a 98 Camaro til it died in a crash, well, cosmetic damage was worth more to fix than the car was worth so the insurance wanted to total it out. I drove that thing to 80k miles on lower graded fuel and never saw any problems mechanically either.

I also owned an 84 Camaro, used lower grade fuel, drove that til it hit 145k miles, never had any mechanical troubles.

The friend of mine who worked at the Lexus dealership in which they had all kinds of cars come thru for maintenance, not just Lexus cars, would see cars with fuel issues all the time. Asked what they used, higher octance fuel. Asked if they liked to race or peeled out at every light, if not, recommended they started using lower grade fuel as the higher grade did nothing for them driving around town, sitting in traffic, etc.

I'm sure there's going to be the one's who tell you to use high octane and the poeple who tell you to use the lower octane, I'll go by my own experiences and what my friend who is a certified mechanic tells me and the issues he deals with on a daily basis at his job...

But like I said, if I drove a Corvette, I'd probably put premium in it cause I'd probably be more proned to drive a little faster, probably one reason I don't own one. Plus I couldn't afford the tires for one, let alone the gas. Personally, I only care if I have a car that gets me from point A to B and back with A/C for the summertime and limit my driving cause I'm concious about other things if you read some of the oil and environment threads lingering around.

Some good info taken from the Exxon FAQ page on fuels:

"Why should I use your premium gasoline (91-93 octane) instead of regular (87) or midgrade (89)?

To find out what octane your engine needs, first check your owner's manual. The recommended level is often 87 octane. Some models have high compression engines which are designed to utilize the octane levels of 89, 91 or higher.

Ordinarily, your vehicle will not benefit from using a higher octane than is recommended in the owner's manual. But if your engine knocks or pings at the recommended octane level, you may need a higher octane gasoline to prevent the knock. Knocking may occur under certain conditions. A small percentage of vehicles may knock because of variations in engines of the same model due to manufacturing tolerances, or because of an unusual build-up of engine deposits during the first 15,000 miles of driving. Other factors such as extremely hot weather, changes in altitude or hard driving conditions (like towing a heavy load) may also cause knocking.

Many modern vehicles are equipped with an electronic device that detects and eliminates light knocking before you hear it. The devices suppress knock by retarding the spark. We believe that some of these vehicles may experience some deterioration of acceleration performance, without knocking, when operating under high engine demand conditions.

Of course, our gasolines have had very effective detergents for several decades. And, because detergent additives help maintain an engine's emission performance, the EPA has required a minimum dosage in all gasolines since 1995. So, while all gasolines now contain detergents, all our gasolines contain additional quantities to better guarantee fuel system cleanliness."

So yeah, you drive a car that recommends 91 or 93, go for it. But in most cases it's not going to do much harm. And cars like like homes nowadays, the average person who owns a home only stays in it for around 8 years, I'm sure cars are even less than that. So if it is going to do damage, you probably won't even have the car long enough to notice.

And also something I should have pointed out, let's refrain from starting our posts with "B.S." We can have a lively discussion without the derogatory words please. If you want to prove someone wrong, go ahead and state your facts, but there's no need to call another's post starting with what is obviously saying bullshit, in my opinion it just shows imaturity. Got a problem with such rules, take it up with Jeremy.

In my car, with 11.5:1 (or is it 11.8:1) compression in an LT5 engine, I'll stick with high-octane fuel, thankyouverymuch. I've run it on a dyno, and I've logged real world driving with diacom on a laptop, and know for a fact that what I posted is absolutely true. I've done the same (diacom logs on the road, not dyno runs) in a base-model 1993 Corvette (LT1 engine) and in a Crapmaro, er, Camaro, and the compression is much lower on those engines. They knock on 87 octane. The ECM pulls back the timing for a bit, and enriches the fuel mixture. Both result in decreased performance and economy.

Believe what you want, but my car is at 179,000 miles and the engine is in perfect shape. Can you say the same for the Camaro at 130K miles? If you ran 87 octane you had internal engine damage but probably didn't notice it - but if you participate in any events, you'd notice it in your timeslips in a big way, or if you tracked fuel economy, you'd notice you'd be getting several mpg less than you did when the car was new.