synthetics for the 8.1L?

04GMC8100HD · August 20, 2003

I'm planning to change to Mobil 1 10W30 and was wondering who was using synthetic oil and what kind?

Randy

tmf6902 · August 20, 2003

I just switched over to Moble 5w30, I had about 27k on the truck when I made the switch so far so good.

8100HD · August 20, 2003

Amsoil 10w40, the 8.1 seems to like a thicker oil. Had 5w30 in it and kept burning it, plus had more cold start knock, with the 10w40 no more oil consumption and cold start knock is minimized.

awdvkd · August 20, 2003

Thats wierd I had worse cold knock with 10W30 dino oil than I had with 5W30 Mobil1. Also when I was using dino I burned more oil. I highly recommend Mobil1 5W30. Its good stuff and very easy to find, is on sale regularly and use can use their products from front to rear bumper. Other synthetic don't offer that sometimes.

raventai · August 26, 2003

I have been using Mobil1 10-30, switched at 1,500 have ~43,000 now. change it when the light says to (about every 5,000) so far so good, weather it will actually pay off in a motor that will last longer enough to offset the higher cost I will never know, but it still gives me a warm fuzzy seeing it come out as thick as it went in unlike dino that gets broke down and thin

I picked it over the other synthetics because it is a commonly available (the 5 quart jugs are finally back at wally world) between the synthetic makers it is hard to pick out the marketing tactics from reality

8100HD: thinking of moving to 10/40 myself the motor is broken in and out of warranty but I am kinda aprehensive of leaving manufacturers recomendations

I grew up in FL always ran 20/50 in all my old beaters, it was always at the thick end of the recommended range for those cars in that climate, as my recip powerplant instructor said "as thick as you can get and still pump" provided the best protection, I did not have to worry about slow oil on cold winter mornings, and here in ga it still is not a big problem, heat is, when I got this truck i was kinda pissed that the thickest allowed was 10-30

do you think GM moved to the light oil soley for milege reasons, or is the motor truely designed with light oil in mind?

thin oil has a slight positive effect on gas mileage, but I did not buy a 500 cube motor with gas mileage as a primary concern

Super Chevy · September 9, 2003

Running Red Line 5w-30...switched at 1,000 miles. 1,700 miles on oil with zero comsuption so far. This truck is used for towing only (approx 9.000 lbs) at 70 plus MPH. Overall very satisfied with Red Line so far.

This 8.1L is nice and quite!... hope it stays that way.

CMNTMXR81 · September 9, 2003

I stuck with conventional "dino" oil (Valvoline specifically) but did switch to 10W30 which as 8100HD mentioned quieted the motor significantly upon cold start.

Chevyfreek · September 17, 2003

I have been running Mobil 1 5w-30 in my 6.0L since 6000mi on the odometer. I have almost 45000 miles on the truck now and have no problems. I think Mobil 1 is one of the best synthetics on the market. I hope to get a lot more trouble free miles out of my engine thanks to Mobil 1. I had read about some testing done on Mobil 1 where than ran it in a car for 300,000 miles and then disassembled the motor to inspect it for wear and most of the engine parts were hardly worn. That was enough to convince me. It would be great to get 300,000 miles out of my Chevy....