Mobil 1 5-40?

[Jeepstang]

The time has come where I need to do my first oil change and I want to go to a full synthetic oil. I have always used Mobil 1 over the years and have never had any issues with it. I was in a Walmart over the weekend and noticed that Mobil 1 has an oil advertised for Turbo Diesel trucks and the only weight they had it in was 5-40 Has anyone used this and it is the correct weight for the truck 6. 7? I think I read that it calls for 15-40

is there another synthetic oil on the market that is 15-40?

 

[RSimmons]

I too like Mobil 1 products but, with the 6. 7, you need to run the API C-J oil correct ? All the Mobil 1 Truck and diesel oil I have seen is still API C-I. As far as weight, the 5-40 works great... . I used it for quite some time in my truck but, decided for my use, the added expense was not justified. I am not going to run oil past 10,000 without testing. When paying for testing, you are half way to paying for fresh oil. So, I am going to stick with the Valvoline premium blue 15-40 dino stuff at 10,000.

 

[Chaw]

Also remember with the 6. 7, the truck decides when it is time to change the oil. I have not been able to go past 3200 miles on an oil change with mine. I am buying Delo CJ oil at sams - 6 gallon case for a little over $50. 00.

 

[roperteacher]

AMSOIL does make a 100% synthetic 5-40 CJ rated oil. Valvolene premium blue is only CJ now as well. No more CI4... . Amsoil also makes a 100% Synthetic 15/40 oil. . but it is NOT CJ rated.

 

[Jeepstang]

change oil now

Also remember with the 6. 7, the truck decides when it is time to change the oil. I have not been able to go past 3200 miles on an oil change with mine. I am buying Delo CJ oil at sams - 6 gallon case for a little over $50. 00.

Mine change oil reminder came on yesterday at 3700 miles

how does the truck decide when it needs to be done?

does it monitor the oil itself in some way? I don't understand

the owners manual tells us something to the tune of change the oil at 15000 with light driving only or 7500 with normal and above normal load use.

 

[JBob Diesel]

The time has come where I need to do my first oil change and I want to go to a full synthetic oil. I have always used Mobil 1 over the years and have never had any issues with it. I was in a Walmart over the weekend and noticed that Mobil 1 has an oil advertised for Turbo Diesel trucks and the only weight they had it in was 5-40 Has anyone used this and it is the correct weight for the truck 6. 7? I think I read that it calls for 15-40

is there another synthetic oil on the market that is 15-40?

You might want to continue using dino for awhile. Everything I have read or heard says not to use synthetic in the Cummins until about 15K-20K miles.

 

[Jeepstang]

15-20k

You might want to continue using dino for awhile. Everything I have read or heard says not to use synthetic in the Cummins until about 15K-20K miles.

Please explain why people on here are waiting that long?

 

[KEpperly]

In my old truck I switched to full synthetic at 3,000 miles and never had a problem. I also only drove it to 31,000 but never had any problems in the 3 years i had it.

 

[JBob Diesel]

My understanding is that the rings need to seat before switching to synthetic and in a diesel it takes that long.