First, let me say I just found this site a few weeks ago and it is awesome! I wish I had found it years ago.
I have looked at lots of UOAs and done lots of searches. Nevertheless, I still want to pose this question to the group about my two vehicles and extended drains. FYI, I live in Texas.
Vehicle #1:
1997 Pontiac Trans Sport minivan with 3.4L V6. I switched to the regular 10W30 AMSOIL on 5/21/02 (60K miles) for the first time. I did the normal engine flush procedure prior to this. I ran this oil for about 10 1/2 months and 10,500 miles with a filter change midway through. I used AMSOIL filters. I didn't do a UOA (never occurred to me). I changed to the regular 5W30 AMSOIL and have been running that for a couple of months now. Everything is fine with the vehicle and I have about 72K miles on it now. I know these engines are notorious for their coolant leaks, but I've had the intake manifold replaced (new design) prior to this last oil change. Anyway, my question is, is it pretty safe to contiue with these intervals using the regular AMSOIL? I know that the only sure fire way is to do a UOA, but I was hoping not to have to do that. Does 10-12K miles on AMSOIL seem reasonable?
Vehicle #2:
2002 Toyota Tacoma, 3.4L V6. I changed the oil/filter at 1500 miles with conventional oil and then switched to AMSOIL XL-7500 5W30 (purchased prior to the reformulation to Group III basestocks) at 5000 miles. I ran it for 6 months/7100 miles and did another oil/filter change again with the same XL-7500 which is in there now. I have the regular 5W30 AMSOIL on the shelf ready for the next change and am planning to do once/year changes. This truck will probably get between 8-10K miles per year with a fair number of short trips. I use AMSOIL oil filters. Remember this is supposedly NOT one of the sludging Toyota engines.
Here are my real concerns/questions:
1) Is it safe to continue with AMSOIL at the frequency/rate I am changing it now? I am basically following the AMSOIL guidelines.
2) Would it be better to say, use Mobil 1/Napa Gold filter and change both vehicles at the maximum mileage recommended in the manual (7500 miles for both)?
That is really what I am struggling with. Mobil would be a little more convenient to purchase and the intervals wouldn't be THAT much shorter. But I've really heard/read good things about AMSOIL and have no complaints thus far. My main motivations are (1) doing what's best for the engines balanced with (2) not having to crawl under my cars any more often than necessary.
HELP!!!! I've got too much information (if that is possible).
David
McGregor, TX
[ July 11, 2003, 11:08 AM: Message edited by: mrdctaylor ]