winter oil change - Page 2

**shiftybullet** · 10-09-2009, 10:25 PM

I was told that once you use 5w-40 you can NOT go back to 15W-40, any truth to this?

How warm of weather can 5w40 be run till?

Kody

**mrmanners** · 10-10-2009, 07:16 AM

Quote:

Originally Posted by shiftybullet

I was told that once you use 5w-40 you can NOT go back to 15W-40, any truth to this?

How warm of weather can 5w40 be run till?

Kody

What was the reason behind not being able to switch back, because I have not heard that before.

You should not user 5W-40 in areas where temps get above 100 degrees F on a regular basis.

**ob_1jr** · 10-10-2009, 07:27 AM

Why should you not use 5w40 in areas that get above 100? doesnt the 40 cover the hot range in the oil? What about all those people that run the amsoil 5w30 year round? Im not buyin that. The lower number is for the cold from what i understand.

Also, the 5w40 by amsoil is a little cheaper than the 5w30. I talked to bigdaddy and he told me that the 5w40 was ok to use in the pre LMM engine. the rating is better than what the other oils are anyway.

Just asking the question as it doesnt matter to me where i live.

maxxflip · 10-10-2009, 07:41 AM

iirc 5w40 -40*C to +40*C and above
15w40 -10*C to +40*C and above
ob_1jr you are correct

**mrmanners** · 10-10-2009, 07:43 AM

Quote:

Originally Posted by ob_1jr

Why should you not use 5w40 in areas that get above 100? doesnt the 40 cover the hot range in the oil? What about all those people that run the amsoil 5w30 year round? Im not buyin that. The lower number is for the cold from what i understand.

Also, the 5w40 by amsoil is a little cheaper than the 5w30. I talked to bigdaddy and he told me that the 5w40 was ok to use in the pre LMM engine. the rating is better than what the other oils are anyway.

Sorry OB1, you are correct, as most OB1's are.

I was going by what was in the owner's manual, not quoting AMSOIL on that one, because I couldn't immediately find an answer for him in AMSOIL information.

None of the information on the premium CJ-4 5W-40, talk about hot weather at all. In fact only information on temps is cold pour point (-51Deg F) and flash point (450 Deg F).

j4nash · 10-10-2009, 08:02 AM

what concerns me about the API CJ-4 Synthetic 5W-40 and API CJ-4 Synthetic 15W-40 Diesel Oil is that Amsoil just pulled the 25,000 mile warranty on them and changed it to 3X OEM but the SAE 15W-40 Heavy-Duty Diesel and Marine Motor Oil still has the 25,000 mile warranty from Amsoil.

The CJ-4 must brake down faster or something for them to switch the warranty on the oil.

**ob_1jr** · 10-10-2009, 08:13 AM

Read the warranty again. I believe it says 3x the manufacture or 25,000 miles or one year without oil analysis.

**ob_1jr** · 10-10-2009, 08:15 AM

actually straight from their site:

Diesel Engine Service
• Three times (3X) OEM* recommendation, not to exceed 50,000 miles/600 hours or one year, whichever comes first. Drain intervals may be extended further with oil analysis.
Gasoline Engine Service
• Two times (2X) OEM* recommendation, not to exceed 15,000 miles or one year, whichever comes first.
*Operating conditions and drain intervals for severe and normal service are defined by the OEM. Refer to your owner’s manual.

**mrmanners** · 10-10-2009, 09:58 AM

Quote:

Originally Posted by j4nash

what concerns me about the API CJ-4 Synthetic 5W-40 and API CJ-4 Synthetic 15W-40 Diesel Oil is that Amsoil just pulled the 25,000 mile warranty on them and changed it to 3X OEM but the SAE 15W-40 Heavy-Duty Diesel and Marine Motor Oil still has the 25,000 mile warranty from Amsoil.

The CJ-4 must brake down faster or something for them to switch the warrant on the oil.

Your correct on recommended change intervals switching to 3XOEM or 1 year versus up to 25k miles or 1 year. But your reasoning behind it is not totally correct. The CJ4 5W-40 and CJ4 15W-40 are new oils for AMSOIL. They have not had the rigorous testing and use that the 15W-40 Diesel and Marine Oil has. Hence the differences.

Also, I posted recently an article regarding fuel dilution in the newer model Diesels. See it here, Fuel Dilution surfaces in some modern diesel applications.

The article talks about how fuel dilution has become a problem in newer model diesels because of the regeneration process for the DPF. While it has not been a problem for the Dmax's, it is for the newer CAT. Take a look at the article above for complete details.

To avoid confusion for dealers and customers alike, AMSOIL changed their recommended drain intervals for ALL diesel oils to match the newer oil.

Hope this clears up the issue for you.

BoiseRob · 10-10-2009, 10:20 AM

Quote:

Originally Posted by zack

i run shell rotella t 15w40 dino oil all year round, and it gets to -50 here at times, never used a winter front, never plugged in, never any issues starting.

x2... Schaeffer #151 15w40 CI4+ dino run year round...