What happens to the engine if you use regular gas instead of premimum gas recommeded for Mazada CX-7?

Answer 1

I agree with Jolly. The reason why it requires 91 octane fuel, is due to the amount of ignition timing advance that the PCM is programmed to run on your particular vehicle application. Using 87 octane will cause it to PING as soon as you put it under load (accelerate). This will damage the pistons over time.

Answer 2

Here's the deal: when the fuel-air mixture gets drawn into the combustion chambers of your engine, it should ignite only when the spark plug fires. If the mixture ignites prematurely (that is, before the plug fires because the cylinder pressure is too high), you'll hear what's called knocking or pinging (it's also called pre-ignition or detonation). This was common in older cars that had carburetors but is mostly non-existent in today's cars because the fuel-air mixture is very precisely controlled. It's an uncontrolled explosion that can damage the engine if it runs too long like this. (too long = weeks, if it's bad enough)

This knocking can be eliminated by putting higher octane (premium grade) gas into your gas tank. The higher octane content prevents the fuel-air mixture from prematurely igniting under higher compression ratios (higher compression ratios = a more powerful engine).

If you drive your car on regular gas (octane = 87) and don't hear the tell-tale sounds of pre-ignition, you don't benefit from burning premium grade gas.
If you drive your car on premium gas (octane = 92 or 94) and don't hear the tell-tale sounds of pre-ignition but DO hear pinging when you use regular gas, you'll hurt the engine if you continue to burn regular grade gas. This is why Mazda recommends premium gas for the CX-7.

In addition to using premium gas, Mazda also recommends that you use the spell checker the next time you Ask a Question.

Answer 3

You will not get the full performance that premium fuel allows. You stomp on it and start pinging , You'll wish you would have used what you are supposed to. If you never drive up hills or never have more than yourself in the car, you could use regular. But if you do use it with heavy load or steep hills and have ping you could lose the top of a piston if it goes on very long. they are now using 11to 1 compression ratios in fairly mundane cars, and that is a mechanical problem as 87 octane has poor controlled burn.

Answer 4

The main problem with using regular in a car that require premium is that the lower octaine gas causes pre-ignition which is very damaging to an engine over time.

Answer 5

i own a repair shop,and its not going to hurt it any at all you may notice a little ping in it once in a while but i doubt you,ll even hear that ,most cars now will run as good or better on the regular unleaded,they did a show on this back in the winter,and it showed very little difference in gas at all, most of the cars that they put regular in,ran as good as the other cars that had premium in them,the only difference is the money you save,which can add up after a while,good luck i hope this helps.

Answer 6

my brother put reg gas in my caddi instead of the others i just went and added some of the expensive stuff to mix it - if its not a whole lot i dont think it will hurt your engine but i wouldnt do it again - maybe change the fuel filter but your car shouldnt break down - mine didnt -

good luck -

Answer 7

It will go slower because it is less combustible, damage your engine over time and void your warranty. But you might save money...

Answer 8

You save money!