Is 7,000 to soon for Synthetic?

[DPKetchum]

Well I didn't just MAKE UP the 15 to 20k suggestion. It was the mileage posted by Cummins on their question and answer site for like the last 6 years and the last time someone linked to said site it still was 15 to 20k or after 2nd oil change. If you change oil BY the book it sounds like 15k to me. Personally I could care when you do it but on engines that do not come with FULL synthetic from the factory waiting for 15k is no biggy for me. Of course some on these sites don't believe in breaking differantials eaither or actually WORKING their trucks like designed.

 

[mberry]

I just looked aon AMSOIL as I have the prefered customer discount and it would only cost me 58. 00 for a case of 12 of the HD 15/40 Synthetic oil. I don't consider that a high cost if I changed every 7500 or so...

I think you will be fine changing to synthetic. I also think that every 7500 miles is wasting your money and good oil. I would go with the "get it tested and let that determine your change interval" crowd.

 

[roperteacher]

Well, then there is the "Warranty" issue. My dealer has no problems with me going to Syn but he did say I had to keep within the specs in the owners manual. I do TOW, LIVE IN DUSTY conditions etc etc etc. . My dealer knows this. If I Installed the Synthetic and oil analysis said your good to go at say 20,000 then I am out of spec regardless. My dealer said according to the owners manual I am not to go over 7500. . I heard that the Syn oil is better for ULSD?? True???

 

[nickleinonen]

I would switch and not worry.

my thoughts too. .



i had about 10k-11k kilometers on mine when i switched [±6500 miles]