Will it damage the engine if I use regular gas?

You apparently have your manual.

Read it.

Trust me.

And keep reading AFTER where it says "use premium gas".

Probably not - I know that the Tacoma trucks "recommend" premium fuel but you can run regular without damage. The knock sensors retard the ignition timing so it will run on the lower grade fuel. If your manual says the higher octane is "recommended" you're OK, if it says it's "required" then not.

That said, retarded ignition timing combined with good driving habits results in a mileage penalty of perhaps 2 MPG. Instead of buying cheaper gas, you may end up saving more by continuing to fill with premium fuel while practicing all of the usual gas-saving driving tips.

-- Mike Harris Austin, TX Group owner,

You should count on the prices never coming down.

I did an 'average' of two cars I drove, my '85 Corolla and my '95 Tercel.

With the better fuel economy I saw using Premium gas, it worked out like this:

Over the 19 year life (on the road...I still have the car..) of my Corolla GT-S, I broke even-it cost as much to run Premium as it would have to run Regular.

With the Tercel, I actually came out ahead. The car got such better economy running Premium it actually cost about $250 LESS running Premium than if I had run Regular!

If you drive a Lexus, you can afford premium. It is usually 20-30 cents more per gallon anyway. If you can't afford that, it is time for something cheaper on gas. John

Thanks smart ass, now try to learn how to read. That is exactly my question, and obviously novices like you don't know the answer.

I'm sure you're one of those idiots that still changes the oil at every 3,000 miles.

The computer will adjust to a lower hp level SO you will probably not save anything It will not distroy the engine. if you get stuck & only reg is available it will work

I would recommend that if the weather is really hot, and you are driving a lot, try and use the highest octane you can afford (if your engine is designed to run with higher octane). Even using mid grade is a help in hot weather. Even putting half regular and half mid-grade in your tank would help. However, always use high quality brands, regardless of the claimed octane level.

Unfortunately, on average, company owned gas stations are more reputable than individually owned stations (my apologies to those individuals who own gas stations). There is a huge incentive for individuals who own gas stations (even those who sell major brands) to fill their tanks with gas that is not the stuff that is advertised. This kind of fraud is not common, but it has happened.

I know the answer, because I know what my owner's manual says.

Mine goes on to say more. Yours does, too.

Huh?

I have seen the same gas delivery trucks at EXXON, SHELL, Speedy, WAWA and others so a big company name on building doesnt' mean quality ensured gas out of their pumps.

I change my oil at 3000 miles.What of it? The way I drive, if I don't I'm letting dirt build up in the engine. How do you think I made it to 223,000 miles?

Charles of Schaumburg

93 Corolla 223,000 95 Previa 161,000

Well, now, that gave me pause for thought. At $30 per, you could change it at, say, 6k miles and pay X over however long you have the car, or you could change it at 3k and pay 2x.

Over 120k miles, then, you could pay $600 for oil changes or you could pay $1200.

If you're turning cars over every 30k miles or so, who cares. But if you keep a car, the extra $30 you pay every 6k miles (for example) is very cheap insurance. A half a cent a mile extra? Especially compared to gas prices, that's inconsequential--especially if it means the difference between a well oiled engine and a sludge-filled engine (hello, Toyota...).

all cars sold in the U.S. must be able to run on Regular gas... I would recommend if your driving conditions are fast acceleration or climbing hills... use a higher octane..

I made my Toyota Corolla to 300,000 miles with 6,000 oil changes, and I drive as crazy as everybody.

3,000 oil changes is just a waste of money. Do you also spend $20,000 a year on "addictives?"

If your manual says 91 octane is required, then yes, using regular could damage the engine. If your car has a knock sensor, your manual will probably say 91 octane is recommended, but 87 octane (regular) may be used as a minimum.

BUT, if you have a knock sensor, it will retard the timing if you use regular gasoline resulting is less efficient operation and lower gas mileage (as well as less performance under load--acceleration, hill climbing, etc.).

Consider this. 91 cctane (premium) normally costs 20 cents more than 87 (regular). At $2.00 a gallon, that is a 10% premium. If the use of regular reduces your mileage by more than 10% (say from 22 mpg to 20 mpg), you will be losing money by burning regular.

If the price of fuel goes to $3.00 a gallon, and the 20 cent extra charge for premium holds (6.7%), it makes even less sense to use regular.

Merritt

You drive a Lexus and don't want to spring for the correct fuel?

Can you actually afford the car?

Ditto what Mike says.

I tracked 20 tanks (10 of 87 octane and 10 of 92-93 octane) in my '05 V6 Tacoma. I stayed with one rating for all 10 tanks to allow the sensors to adjust, I didn't switch back and forth. I actually have MPG data and fuel cost data all the way back to day one (11 miles) in the "memo" field of Quicken. If you charge your gas, and fill every time, this is really simple to do just by writing the mileage on the receipt.

I found that the cost per mile is now pretty much identical ($3.05 vs. $3.35), so I stayed with premium. When gas was $2.00 or 87 vs $2.30 for

93, regular was cheaper, but only by 2-3 cents a mile.

That's because bulk delivery is outsourced. The truck is filled from different distributors, depending on the delivery company's customer.

Says who?