Automania/Repair and Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 45

by Bob Hagin

Q. I have a '73 Pontiac Grand Am with a 6.5 liter engine and I'm wondering if it has value as a classic. It has a tan vinyl, brown paint and tan Naugahyde bucket seats. It is a two-door model. This car has been kept in a garage its entire life and serviced regularly every 3000 miles. It has over 120,000 miles on it and can still go 3000 miles without having to add oil. I had to replace the grille as the result of a confrontation with a deer. The only one available was a junk yard item and being that my car was a centennial model, some parts are scarce and my replacement grille has developed some cracks around the headlights. Are there shops around that repair plastic grilles? Where would I advertise this car if I wanted to sell it? R.R. Norfolk, VA

A. Your Grand Am was something of a bright spot in an otherwise lackluster decade for Detroit iron. It had good lines, pretty good power (but better if it carried the optional 455 inch "X" 310-horse engine) and for the most part were pretty well turned-out. The grille problem shouldn't be too hard to solve but you'll probably have to find a specialist though the ads in a magazine like Musclecar Review, a monthly "buff book" you can find on magazine stands in the bigger book stores. Selling it will be tougher. The Grand Am isn't as desirable as a Pontiac Trans Am of the same vintage, so you'd have to find the right buyer. There's a couple of them listed in Hemmings Motor News now for around $3500, which is probably a pretty fair price for a good one.

Q. What is the value of high octane gasolines? Are they worth the money or not? I have a new Toyota pickup truck and I'd like to treat it as well as I can. Should I invest in premium gasoline? D.R. Junction City, OR

A. Without going into a technical dissertation about Reed Vapor Pressure, Research Octane and a lot of other technical stuff that I usually don't explain correctly anyway, I'll tell you that octane rating doesn't have much to do with fuel quality. What we refer to as "gasoline" is actually a mixture of hydrocarbons that are "tailored" to give the best "localized" performance. The "mix" is usually blended to vaporize at a lower temperature in the winter, which makes starting your vehicle easy, and to vaporize at a higher temperature in summer to prevent vapor-lock. An octane rating is something else. "Octane" is a very "pure" unblended hydrocarbon that burns at a very precise rate under very controlled lab conditions. Its "burn" rate is given the number 100 and everything that burns slower is given a higher number while everything that burns faster is given a lower number. High compression engines require a slower fuel burn rate to prevent pinging, while lower compression (and less powerful) engines can digest cheaper (to make) lower octane fuel. If your engine isn't built to require high-octane fuel, it won't help to put in the high-test stuff. If you follow the makers recommendations in your owner's handbook, you won't go wrong - as long as you buy a name-brand gasoline.

Q. We have a 1989 Chevrolet Corvette that we have had since new, and originally it ran very well. We aren't "enthusiasts" and use it for daily transportation to in stop-and-go traffic. Over the past few months, we've noticed that the car has become sluggish and somewhat hard to start. Our mechanic says the car needs to have its fuel injectors cleaned and that it can be done on the car using a special "kit." It isn't an inexpensive job, but we've always used a gasoline that claims to clean injectors as you drive. Should we have the job done? T.H. Battle Creek, MI

A. Injector detergents in gasoline work pretty well, but injectors can still build up deposits. If everything else checks out on your Corvette, a cleanup job on the injectors will probably be a good investment.