[Rookey]

I am due for my first oil change. I only have 4000 miles and the DIC says 50%. I’ve owned the truck for almost 1 year. We live in the Sacramento valley area where temps range from the 20’s to 115 F. My driving is mostly stop-and-go city driving – 3-4 miles. We pull a fifth wheel about 6-8 times a year for weekend getaways.
The Duramax manual says a 15W 40 would be best for this kind of climate. I would like to go with a synthetic. I have been doing Internet research as well as talking to dealerships in this area. I am getting such a mix of recommendations from the dealers, that I’m tempted not to listen to them. One says don’t use synthetics because they don’t meet the CH-4, CI-4 requirements. Another recommends a syn blend made by Kendall. My local dealer recommends Chevron Delo 400, which he says is very good. I have heard the same thing except it’s not a syn. I like Mobil 1 but they only offer 5W 40.
I was swaying towards Amsoil except it’s not API certified for the syn-type oil – at least that is what I have read. Something about having too much of a particular additive that is good for lubrication but clogs the cat. I also would rather trust my mfg warranty than theirs.
Would appreciate comments from anyone who lives in a similar environment with the same kind of driving conditions. I’m curious if this Mobil-1 multi-grade would be sufficient for my needs?

Sorry about such a long-winded post, but I wanted to mention everything I have encountered and explain my frustration on selecting a good syn. Thanks for any information.

Mike

 

[eggsack]

The Amsoil 15W-40 is one of the best if not the best oil offered by any company in full synthetic. All Amsoil oil is certified just as any other oil.

I have been running Amsoil exclusively in my trucks since 98. I had a 01 that I traded for my 06 and the motor inside was spottless. I ran the Series 3000 5W-30 Amsoil in it along with the Dual Remote Bypass system and my oil changes were just about 80,000 for the first one and 160,000 for the second one. I changed both filters at about 25,000 miles. Running Amsoil and the remote bypass is the MOST cost effective way to give the engine the best lubrication and save you $$$$ to use for something else you want to buy for it.

I personally do not like people gettin on here and saying do this or do that. Do what you want, but Amsoil will save you big bucks and help pay for those mods we all want.

 

[RayMich]

GM is only looking at dino oils when they make their oil recommendations. 5W-40 and 15W-40 are both 40 weight oil at high temperatures, but synthetics are way more stable and more capable of handling the higher ambient temperatures than their dino counterparts. They also have much better cold flow characteristics.

Any of the name-brand synthetics will work fine for your driving conditions. Just make sure it is for diesel engines and it is at least CI-4 or CH-4 certified. The new CJ low ash oils will also work on your truck, but are more expensive.

I use Shell Rotella-T Synthetic 5W-40 in my '06 LBZ year 'round. It is CI-4/CH-4 certified and you can generally find it at Wal*Mart for around $15.95 + tax per gallon. Mobil-1 Turbodiesel Truck 5W-40 and Delvac-1 Synthetic 5W-40 are the same oil according to Mobil, but more expensive and much harder to find around here.

Don't forget to at least check the rear axle fluid. Many members have found their trucks to be WAAAAY low. Mine was 2 1/2 quarts low !!! Make sure you use synthetic fluid for the rear axle.

 

[Rookey]

Thanks eggsack and RayMich. I did some calling around here and found a Napa store that is selling the Mobil-1 Delvac 15w-40 by the gallon. The price is $9.50. He says "man that's pretty cheap". He verified the price. Isn't this the oil that was replaced by the Mobil-1 Turbo Diesel 5w-40? It's a good price, so I may go pick some or should I go for the 5w40, assuming I can find it?

 

[TOTHEMAX!]

i run amsoil 5w-30 hdd diesel oil, its great stuff. you will find many diffrent opinions on what oil you should run on this site. whatever synthetic oil you do choose to go with will be superior to the dino oil you are already running.

 

[RayMich]

Mobil-1 Delvac 1300 15W-40 is very good diesel oil, but it is NOT synthetic; it is dino oil. If you want the synthetic, you'll want to look for Mobil Delvac 1 Synthetic 5W-40 or Mobil 1 Turbodiesel Truck 5W-40. Big difference.

AVLubricants Inc is a supporting vendor here and carries Mobil products.

 

[BigdaddyG]

AMSOIL is not API certified.

 

[TOTHEMAX!]

AMSOIL is not API certified.

yes you are correct, some of their oils are not API certified. this has been discussed in many other threads. mainly it is because they are always changing their formula to better the oil. to certify it every time would get costly and since their oil already exceeds the minimum standards set forth by API it would also make so sense to certify it.