Does anyone here put premium in their car? If not, but it's one of those cars that says you should -- why not?

My car runs noticably better on the higher grade gasolines. Usually I go with the mid-grade, but never the regular.

From my first link:

Automotive experts say using regular gas in most vehicles does no damage and makes no discernible difference in performance. Cars made in the past 15 years have such highly refined computer controls that the engine will adjust to the grade of octane in the gasoline, even in cars sold as requiring premium gasoline. Some drivers — in some cars under some driving conditions — may notice a drop in horsepower, but for most people behind the wheel, it wouldn’t be enough to notice, the experts say.

On Car Talk one time they recommended that someone do a blind test on their spouse who insisted that more expensive gas was best, IIRC.

Ever since I replaced my engine two months ago, I've been having intermittent problems with the "check engine" light appearing on the dashboard. It goes away when I fill up with premium, so I'm sticking with that until I get a new car in 2006.

Kathy A, your car specifies premium gas?

No, but it is over 103,000 miles, so I'm babying it until I can afford a new one.

Well, most experts say that putting premium in a car that specifies regular has no extra benefit. I'm mystified, however, as to why your check engine light goes away when you add premium.

Stupid wanker mail carrier didn't ring the doorbell!

Hey, at least he came to your door. Last time I had a UPS package, the guy just wedged the delivery slip into my mailbox, didn’t even bother to walk up the three flights to put it on the door.

Huh. They interview a mechanic that says substituting regular unleaded for premium is bad - that's a minority opinion I think.

I asked my dealer about it, who theoretically has no stake in what kind of gas I buy, and he told me that using regular unleaded wouldn't hurt the car, but it would run much better on premium. So, these days I spend about $37 to fill my tank. Fuckers.

Here's what Cecil has to say:

[link]

After reading my two links and the Cecil link I'm still confused.

OK, higher octane reduces or eliminates detonation. That makes sense. Detonation is when the fuel/air mixture spontaneously ignites (under the heat of compression) before the sparkplug fires. This is bad. But modern engine computers can detect detonation, and retard the spark to prevent detonation. Except retarding the spark means the spark happens later - i.e. the spark still happens after the detonation, so I don't see how that helps.

A lot of automotive experts are confused about this, or have contrary opinions, so I don't feel too bad about my confusion.

eta: And I think the Washington Post thing I linked to has several errors, so that doesn't help my confusion.