QUESTION: I bought a 2008 Cheverlet Impala LS new in December 2007. The driver’s-side door panel recommended 30 psi in all four 225-60R-16 tires. I religiously kept 30 psi in these tires, (my ONSTAR account will verify this fact), but they continued to wear very badly on the outside of each tire.
QUESTION: I bought a 2008 Cheverlet Impala LS new in December 2007. The driver’s-side door panel recommended 30 psi in all four 225-60R-16 tires. I religiously kept 30 psi in these tires, (my ONSTAR account will verify this fact), but they continued to wear very badly on the outside of each tire. The tires were rotated at the proper intervals, and on two occasions I had my front end alignment checked, and it was OK. Due to these tires wearing down so much on the edges, recently I had to replace all four tires at 34,000 miles. I personally think I should have gotten more mileage on these tires. The person from whom I bought the new tires told me GM recommends 30psi for a softer ride, but tires this size should be inflated to at least 35 to 37 psi. I would like to know your opinion of the correct psi for this size tire and if I have any recourse pursuing this matter further with GM.
ANSWER: The tire wear you mention is from an alignment problem. The tires should not wear on the outside edge or inside edge. Tire tread patterns are also an important factor with vehicles. As far as GM getting involved with the tire wear problem, this is something you and the shop service advisor should have been involved with making sure to correct the alignment problem. As for the expected mileage from your tires, I would expect to see 40,000-plus in mileage, not the 34,000 miles. I have some customers that get 30,000 miles and some get 60,000 miles out of tires. I have no problem with even tire tread wear, at the 34,000-mile marker on your car. The problem is uneven wear. If the tires are worn on both inside and outside edges, the air pressure is too low. If the tires are worn in the center the air pressure is too much. Any deviation is an alignment problem.
QUESTION: I have a 2001 VW Cabrio with 81,000 miles. Recently a trouble light would come on calling for antifreeze. Adding antifreeze corrected the problem temporarily, but soon the level would be down again. This condition has been getting increasingly chronic. My mechanic inspected the cooling system and could find no leaks. He wondered if perhaps the antifreeze was getting into the engine via a faulty gasket. He asked if I have seen any white exhaust, but I have not. Nor has the engine been missing, nor is there a check-engine light. Any thoughts?
ANSWER: The first thing to keep is an engine can induce antifreeze without any white smoke out the tailpipe, or any engine skip and or a check-engine light illuminating. Have your technician add some dye to the coolant and then pressure test the system for a good hour, not just a few minutes. The next step is a check for any exhaust gases in the cooling system with either a gas analyzer or chemical test. There are also some factory coolant tablets to help seal the coolant system. We call it coolant stop leak.
Junior Damato writes regularly about cars. You can send questions to him care of the Old Colony Memorial, 182 Standish Ave., Plymouth, MA 02360, or e-mail firstname.lastname@example.org.