Just bought me a new GMC Sierra and want the best for it, I know their are alot of guys in the automotive industry on here and I would like some opinions on synthetic lubricants, engine, ATF, ect. I was thinking of changing the engine oil it came with after 1000 miles and putting in 5w30 Mobil 1, so tell me what you think and please NO sales pitches from you Amzoil dealers, just the facts please.

I use synthetic ATF in my transfer case & synthetic gear oil in the axles. Regular Valvoline or Castrol 5W30 in the engine.

My brother uses synthetic oil in his 2000 GMC K2500 (6L). I've sent him an email asking him what brand he uses.

This is what bobber sent me about the 0W30 they use in Alberta (temps in Metric)

Petro-Canada. We have extreme weather temps here,from -40 to 35 above. Syncrude runs this oil year round in all light vehicles, except the Duramax diesel. A few years ago they did a cold start up test at the Research Dept involving 0-30, 5-30 and 10-30 oils. Not sure what the ambient temp was but they used Chevy 350's for the test. It took 10-30 2minutes 11 sec to get adequate oil to the rocker arms. 47 sec for the 5-30 and 9sec for the 0-30! I found that hard to beleive so I took a liter of each oil and placed them in our freezer for 2 days then tried to pour it out of the container. Try it and the results will surprise you! We have GM tech's on site to maintain warranty claims on these vehicles and GM approves the use of this oil year round. Hope this was the info you were looking for.

Well what else needs to be said other than the Corvette comes stock with it and so does several other Hi-Po vehicals and bikes. I've run mobile 1 and Castrolturbo approved oil both with great results. You may want to just run a semi synthetic oil instead as it's alot cheaper. You can longer between oil changes also like 5K to 6k. I'd run it in the tranny especially and the rear end if you tow just as a precaution.
Caleb

What is syncrude(mnfr).? And what else can you tell us about 0-30. How does it work in 70-100deg. temps? Can we buy it here in the US and how much?
Caleb

Syncrude is a tar sands open pit mining operation in northern Alberta near Ft. McMurray. It gets mo fo cold up there.

Petro Canada is a chain of gas stations up here. Any members who live in the US, just across the border would be familiar if they've ever crossed over to here. The only problem is some stations don't stock the 0W30. You might have to contact a bulk or commercial dealer.

I'm not sure what GM's Oil Life System is set up for in the '02 trucks, but I know the drain interval is longer than my '00.

The rear axle gear oil has been synthetic since '00. I'll check at work what weight it is.

The best oil for your car or truck is AMSOIL. *However amsoil is very expencive, but if you want the best thats it.

I have a lot of experiance in CASCAR racing. *Amsoil works in ways other oils dont. *For instance it doesnt burn.

An other good oil is Castrol Syntec. *Its not a 100% syntetic but it works good in any engine. *This is what i run in my truck. *

I have seen the inside of at least 25 cascar engines and castrol does work.

Mobil one is more expencive but does nothing more then castrol. *

But once again. *The best is AMSOIL.

My brother says he uses Mobil 1.

I've used Valvoline Durablend (semi-syn) for years, and won't change. *Back when I had a 77 t-bird that leaked out the rear main, I once put Quaker State in it and that crap leaked out 6 quarts in 400 miles. *Durablend only leaked out about 2 quarts every 500 miles.

I run amsoil in everything http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/biggrin.gif . *I ran the 0W-40 in my ATV with no problems. It was a great all year round viscosity good for extreme cold and heat. To get substantial savings in amsoil i became a dealer, 40 canuck bucks and i saved the money on the first case 4x 4L of injector oil. My dodge ram diesel is Amosiled from front to back . series 2000 75w-90 in both diffs.. amsoil ATF in the tranny and transfer case. and 15w40 heavy duty diesel and marine oil in the motor. I am thinking of tring the amsoil series 3000 5w-30 heavy duty diesel oil this winter for those long runs to Cochrane.

Just a note on the mobil 1 oil or should i say fact as tested by an independent lab> The test was a four-ball wear test(ASTM D4172B) 40kg pressure @ 150'C, 1800 rpm for 1 hour duration. *Wear scar diameter in mm -- amsoil HDD 5w-30 =0.396. *mobil 1 synth 5w-30 =0.696. *In simple terms the mobil had almost twice as much wear as the amsoil. http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/wow.gif

Yeah, No other oil is as good as amsoil says pretty much all tests done by factory, racing teams, and independent. *Its really good stuff.

By the way Castrol Syntec in that same test mentioned by permafrost is .576.

Thanks all for the replies that was the kind of info I was looking for, I would like to learn more about the Syn. ATF and what can be used in the GM auto transfer case as it specifies somthing other than ATF, maybe their fluid is the best, as far as the 4 ball wear test goes, I have seen that so many times on different web sites I can see it in my sleep, the Mobil 1 they are using for comparison is not even used anymore and some of the other oils are petrolem, I have not formed any opinions yet as to what brand to use but these guys need to test apples to apples to convince me with a colorfull chart.

Even though my 98 Ram SS/T is a company truck I still use synthetic Mobil 1 in the motor and synthetic Dexron in the trans. *The only thing that gets regular lube is the posi rear end. *I keep with the specs on that one. *Still running great at 106,000 miles.