I've been following this thread for a while and I read the same SK article Dick referenced. Curious, I checked several oil analysis reports on my vehicles (www.blackstone-labs.com) and found that the Pennzoil 10w-40 I use in my gasoline engines shows between 500 and 900 ppm of zinc. The Chevron Delo 400, which I use in my motorhome's Cummins 8.3 turbo diesel, shows around 1500 ppm. The oil analyzed for the gas engines had about 4,000 miles on it; the Chevron had about 8,000 miles of service. So it looks like the Chevron Delo ends up with roughly twice the zinc as regular oil and this supports the SK findings. For those interested in oil analysis, Blackstone does a nice job for the money: $20 for a single analysis and about $15 if you prepay for 6. They provide a sample collection kit and a written, or electronic (pdf) report. If anyone would like to see one of their reports, contact me directly and I'll share one. For what it's worth, I'm going to switch my Imperials to the Chevron product. It's available at Sam's Club in the 4 gallon case. Phil Brust 73 and 82 Imperial ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm