Which octane gas for 04 Corolla?

Plus doesn't contain any more energy that regular gasoline. And it takes more energy to make, which is why it cost more.

If you're driving it hard enough to feel a difference on a regular basis, you're abusing the car.

Chances are that the car performed better on the higher gasoline only in his mind.

You can try and measure the mileage difference on your own. But your best bet is to use regular (87 octane) fuel and drive conservatively. You'll save money and save energy.

Jeff

The brand of gas means more than the octane level.

Just run several tanks of whatever you like and see for yourself. It's not hard.

In that car, what I'd do is run three to four tanks of Shell 93 with V-Power. This will clean out the intake and combustion chambers. Check your mileage per tank. Then after that continue to run Shell 87 octane.

87 octane is all you need, but not all gasoline is made the same. My experience with a 94 Lexus, currently at 174K miles, is that Shell 87 in a clean system costs less to run per mile than anything else--even though per gallon it costs more.

Do you have any scientific studies that back your claim? Gasoline is gasoline. The only thing that changes is the additives. And there are only certain additives that they can add to make the winter formulation.

Jeff

A bottle of Techron would be much cheaper than the extra cost of 3 tanks of premium gasoline.

And using regular gasoline just as effective and much cheaper still.

Jeff

I have an '04 Corolla & have had Corollas since '84. Have never put anything except "regular" into their tanks. OTOH, I've never experimented with a slightly higher octane to see if it made any difference re: MPG, but then something tells me it wouldn't...

Cathy

Related subject - refresh my memory: With a modern vehicle like the ones we're talking about, what causes knocking? The advice used to be "User higher octane gas", but my mechanic said "No - it could mean your {missing idea} has/is a problem". What's the idea I'm forgetting?

Anyway, he said moving to premium gas would stop the knocking, but it just masks a problem that should be fixed. Solution: Drive twice a month with the radio off, passengers bound and gagged, and listen to your car.

Gee, you left yourself way too open. I won't even try. ;-)

Did the mechanic say the knock-sensor or EGR valves? The knock sensor senses knocking and retards timing.

And if the passengers are in-laws, make it at least once a week.

Jeff

Yeah...probably one of those.

Don't remind me. My mother in law took only 30 seconds to get carsick, sitting in the front seat. It reached the point where I had to learn a whole new way of driving, by visualing a full wine glass on the hood. Can't spill the wine or make the glass slide or tip. What a pain in the ass, trying to switch from Mario Andretti mode to old fart mode.

1995 Tercel. Bought it with 99,990 miles on it. Owner had used 87 Octane. I NEVER use 87 Ocatane. Filled it with 89 and reset the trip meter. After a few tanks of 89 Octane, did the calculations and came up with 36-38 MPG combined driving.

Now, I usualyy don't use 89 Octane either. So the next few tanks were 93 Octane. After a few tanks came up with 44-46 MPG.

Figuring when I owned the car gas was ~$1.65/gallon for 87 and $1.75 for

93, I figure over the time I owned the car I SAVED $220 by using 93.

Your mileage may vary. The only car I ever had that has bucked this trend is an '89 Mazda 626 I currently have as a winter beater, and it gets better MPG with 89...

Vehicles with electronically controlled spark advance can benefit from higher octane, but the benefit does not always outweigh the costs of the higher octane fuel. I recommend that you try 3 or 4 tanks of premium, then

3 or 4 tanks of mid-grade, and then 3 or 4 tanks of regular. Monitor your fuel economy and see if you can measure the difference. If you cannot tell, then use the 87 octane.

Don't measure fuel economy; use a good gas, and measure your fuel cost per mile.

If you'd like, then use grocery store gas and measure your fuel cost per mile.

I think you'd be surprised. "Yeah, but the grocery store gas is cheaper!"--but only the purchase price, not the per-mile price.

Do you have any real evidence that the name-brand gas gets better mileage?

Yeah...

Good point, it's fuel cost per mile that is relevant.