Regular vs Premium at 7,500 feet in elevation?

[SteveSS]

I have a car that requires Premium. I've put regular gas in it aand have noticed no differences. The car is a '97 so it has a computer that may be making adjustments. We lose so much compression here, especially where I live. My understanding is detonation is related to compression. So Colorado assumes we lose so much compression here they can downgrade the octane of gas. Since Premium is almost a buck a gallon extra I don't want to waste money. Am I hurting my engine? I've never heard a knock or a ping.

Regular, Mid Grade and Premium.

Colorado

85

87

91

 

[496 polara]

If you aren't experiencing detonation then I don't know how you could be hurting the engine. Run the 87 but if you hear it detonating switch back to premium. Or mix it half and half if you want to feel better about it.

 

[R413]

You won't hear it ping, the computer will retard the timing.

It say it needs premium, it doesn't day you can cheap out at a mile high and use regular.

How well do you like the car?
How long do you want it to last?
How hard do you drive it?