comments on oil

[tammlyn]

hi guys i purchased my lbz sierra dually in december 09,when i purchased it, i did a full service and put in 5w40 full synthetic,when summer come i put 15w40 semi synthetic now i really didn't see any difference on idle oil pressure,high rpm oil pressure is the same now i am due for a service before towing season, are weather usually plays between 10 to 30 degrees celcius should i just stick to 5w40 full synth. or go back to 15w40 your comments and opinion would be app. thanks mike

 

[Bammer]

Both oils are a 40 weight when up to temp so I say stick to the 5w40 for the added cold start flow benefit and run it 10k miles between changes . Duramax engines have proven through oil analysis to be very easy on oil.

 

[Mad Maxx]

I Use Amsoil 15w40 all Year round and don't have any Problems.

 

[btfarm]

I use Rotella 15w40 year around with no troubles but I do believe you can't go wrong with the synthetic.

 

[tammlyn]

oil

i can't use 15w40 all year as are winters temp stay in the -40 for 6 to 8 weeks sometimes the winshield is in the high -40 and -20 to -30 for a couple of months

 

[btfarm]

Then I'd say stick with the 5w40 syn year round

 

[CtChevy427]

You will be fine running the 5w40 year round. As stated above once it's up to operating temperature it's all the same.

If you really want to know how well your oil/engine is working I would suggest a UOA. This is the tell all as far as whats wearing and the all around operating condition of the engine.

 

[Heartbeat Hauler]

I use Rotella 15w40 year around with no troubles but I do believe you can't go wrong with the synthetic.

This is what I do also. I plug in during the winter just to help the starter live longer. x2 on the syn oil.

i can't use 15w40 all year as are winters temp stay in the -40 for 6 to 8 weeks sometimes the winshield is in the high -40 and -20 to -30 for a couple of months

But, as other's have stated, with those winter temps I would stick with the 5w-40 syn all year round

 

[12ga diesel]

I've ran both 15w40 and 5w40 syn and both are very good. If you are concerned about the cold weather with the oil, then I agree with everyone above and say stick with the 5w40.

 

[tammlyn]

oil

i wasn't worried about winter i know 5w40 is the way to go ,what i was wonwering is th 5 weight heavy enough for summer starts as its quite lighter than 15 at start ups,i was wondering if anyone else was using 5w40 all year thanks mike

 

[CtChevy427]

i wasn't worried about winter i know 5w40 is the way to go ,what i was wonwering is th 5 weight heavy enough for summer starts as its quite lighter than 15 at start ups,i was wondering if anyone else was using 5w40 all year thanks mike

I have run the 5w40 through summer and winter before. There were no problems with the hot of the summer months at all. The UOA's came back fine.

 

[12ga diesel]

i wasn't worried about winter i know 5w40 is the way to go ,what i was wonwering is th 5 weight heavy enough for summer starts as its quite lighter than 15 at start ups,i was wondering if anyone else was using 5w40 all year thanks mike

I am curently using Mobil 1 5w40 and have used it year round since about this time last year. I have had no issues running the 5w oil year round. I have ran it in other trucks as well in the past during the summner and again with no issues.

 

[tammlyn]

thanks for your comments guys i will stick to the 5w40 all year round

 

[Ed HD]

I keep Amsoil 15W-40 year round in our 05, no problems even when it's below zero. However, you're a lil further north, so the 5W sounds like a better option. I concur that it will be fine year round.

 

[rtquig]

I used to switch back and forth between the two, but the last few years decided just to use the 5W-40 Mobil 1. Towed a fifth wheel in the summer and all was fine. As others have stated, you can go to 10K easily with synthetics, but as recommended a UOA would give you a better peace of mind.