It is hard driving that causes valve wear. Usually long ,high speed drives on the interstate, especially with a large load or towing a trailer/vehicle does the trick, especially if you do a lot of uphill driving.. For the easy usage most of our Imps gets, I wouldn't worry about valve recession, unless you're repairing previous done damage. But, if you plan to tow, take long journeys or carry heavy loads very often, go ahead and have a set of hardened exhaust valve seats installed. End of problem. Phil <>< ----- Original Message ----- From: "John Harvey" <harvey5691@xxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Wednesday, September 11, 2002 7:02 AM Subject: Re: IML: Additive to moderate valve wear > I have been driving a 1951 brand P car for more than 20 years without using > any additives to suppress wear, and there doesn't seem to any damage. I > have probably driven 40,000 miles in it, and the engine was old when I > started this. I have used gas with and without alcohol in it and not noted > any difference in the way it runs. Nor have I had any problems supposedly > blamed on alcohol in the gas. I use 10w30 motor oil in an engine originally > designed for non-detergent oil. Yes, it uses some oil, but it always did. > Most of the people who claim valve recession and other wear have high > performance cars, and drive them that way. I suspect hard driving has more > to do with engine wear (Surprise, surprise) than the lack of lead in the > fuel. I have a 57 Allis-Chalmers tractor I use for things like driving an 8 > foot wide snowblower, and dragging a 16 foot batwing mower, and it > seems to be quite happy with the cheap non-lead fuel, too. > > JOhn