I am hoping this will not turn into some Great Debate about how “Me and Billy-Bob have used Shell 83 Octane in the tractor for 25 years, it’s the best!!”
In the post about oil, someone’s friend tested oil and found which ones were the best.
Is there anyone who has scientifically tested different brands of gas, or know someone who has tested them, or read a good article. Ok, anyone ever hear a rumor at least?
I am looking for a good REAL answer. Not an opinion. Your opinions and stories are welcome, but let’s keep this a GQ and not a GD or IMHO.
I use Amoco’s 93 Octane. It has techron in it which is supposed to clean the engine too. Does it? Is it a gimmik? Is it the best, cleanest gas?
I am not sure if there are RaceTrac gas stations everywhere, but my friend’s uncle works for the Department that inspects the gas around here, and he says RaceTrac is always being fined for having to much water in their gas. So the answer is definitely not RaceTrac. See how science works…
Ok, not stop stalling and answer the question!!
There have been a number of tests/studies. For all intents & purposes, any good “name” brand is about the same as any other. All these have a “detergent” like “techron”. Do you really need Premium?
And as for oils, all the premium oils are about the same, also. Synthetics are a different kettle of fish, while clearly better, they do not seem to be worth the price.
I don’t know… maybe you guys could tell me. I would hate to think I was wasting my money all this time, especially with the high prices lately. Isn’t it better?
Well, yes and no. Premium is less likely to detonate, so it can withstand higher compression. Higher compression will provide more power, all other things being equal. On the other hand, you can’t increase the compression ratio of your car without really sinking some $$ into it.
Use whatever your owner’s manual says to use. If you’re using a higher octane gas than recommended, you’re not doing any harm to your car, but you are to your wallet…and you’re not getting any benefit from premium, either.
I’ve found that regular unleaded is just fine for every car I’ve ever driven, except one. My company had a '93 Saab once that had to have super premium or it ran terrible.
Also, I’ve found that every brand of gasoline is identical, once again except one: CLARK. Every time I’ve filled up with gas at a Clark station, the vehicle ran something awful. It didn’t matter what kind of car I was driving, or what filling station I went to, Clark brand gas always made the vehicle run as if there were water in the tank. Over the years this has happened to me with at least 12 different vehicles (including 2 motorcycles) and 6 different stations. Clark gas tends to be the cheapest, but it sucks. Every other brand is the same.
A lot of people seem to think that premium gasoline gives better gas mileage. In general, I find the opposite to be true. That is, low-octane gives better mileage than high-octane from the same gas station. Chemicals added to gasoline are oxygenates (to produce a cleaner burn [less pollution]) and octane-boosters (for their anti-knock properties), among other additives. Many chemicals, like MTBE and ethanol, serve both purposes. Both of these, however, have less energy content per gallon than straight gasoline. My advice: Use the lowest-octane gasoline that gives acceptable performance.
bear- unless your owners manual says to use it, yes you are wasting your money. Use regular, or the middle pump. premium is not “better”, just higher octane, which your car cannot use unless designed for it. Note, however, if your current car is tuned for premium, you might need to have it retuned to run as well with regular. So, change a tank or 2 before your next tune-up.
There are some offbrands that do not add detergents. Some add ethanol, which is not good for some cars. Some do, indeed, have water in the tank.
Well, I don’t know if this counts, but to me gas was gas – unless bought from real cheap stations at those little stores. (Because they often buy gas from several dealers so what you get is a mix full of different chemicals, alcohol and/or water. Shell might go in one day and Exxon the next.)
Anyhow, I bought Shell regular for my mower – the station being closest, if by no means the cheapest. One time I bought premium – and there was a difference in performance. My lawn mower is old and cranky. To shut it off, one turns off the gas and let it sputter to a stop or grabs the plug wire, risking shock, and pull it free. (Hell, once started, it runs good!)
On the premium, after I stop the gas flow, the damn thing runs on seemingly forever! That just on the little fuel in the gas line!
I run premium in my big old station wagon now. I actually seem to get better mileage!
The general rule is run the lowest octane you can, as long as your car doesn’t knock and ping. If your car is in proper running order, then the lowest octane that doesn’t have premature detonation will give you the best results at the lowest price.
Many cars (like my Saturn) recommend against anything but the lowest octane since higher octane gas can actually damage the engine. My guess is that all the gas wouldn’t burn or burn late in the cycle, doing damage to the downstream parts.
At altitute (like Denver) the octanes used are roughly 2 lower than at sea level; ie regular is 85, mid is 87, premium is 91. I’m guessing this is due to lower air denisty, but I hope others can fill in.
And, as others have said, there is actually less available energy in premium gas. But it does allow high compression in the engine, which generates more power, IF your engine is designed for it.
IIRC the high grade fuel retards the burning of the fuel so it explodes later in the compresson stroke. the only reson to get the high grade stuff is if your car pings using the lower grades under normal loads THEN use the next grade up. I also read, sorry no link, a web page once where the author said to change brands of gas every 3000 miles because each brand has a different cleaner to it. I still don’t do that, probably should though.
You MIGHT be doing harm to your car very slowly by running premium if it isn’t designed for it. Since premium burns more slowly, it may not burn completely, therefore increasig carbon deposits inside the engine. This will eventually lead to problems such as plug fouling. The increased deposits can eventually raise your compression ratio, causing you to need a higher octane gas to maintain performance.