Posted by HWooldridge on Thursday, December 05, 2002 at 11:27AM :
In Reply to: Anyone use Mobil 1 10W30 synthetic oil? posted by Tom in Boise on Wednesday, December 04, 2002 at 11:58PM :
A petroleum engineer told me not to switch back and forth between conventional and synthetics. Pick one type and stick with it or the seals start to deteriorate. I have been running Mobil-1 10W-30 in my '98 Ford with a 460 since the first oil change and have not been religious about changing at 7500, sometimes having gone to 10K. At 102K miles, I have no leakage, burning or loss between changes. I had a '93 Ford with 7.3 diesel that I sold at 170K miles with no issues. However, changing filters more frequently is probably a good idea.