Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: dans96u295ft on May 24, 2025, 09:15:56 am

Title: Full synthetic oil
Post by: dans96u295ft on May 24, 2025, 09:15:56 am
I switched to 5-40, Rotella full synthetic and added a cetane booster to the fuel before my trip this week. Pulling a 5000 lb trailer, The Cummins just purred there and back. I'm convinced it has more power and oil pressure is quicker upon start up. I've been using the cetane booster for several years so the only change was the oil.
Very happy!
Title: Re: Full synthetic oil
Post by: John44 on May 24, 2025, 06:27:41 pm
Why did you go with 5w40 instead of 15w40,the 5 is probably the better mileage.
Title: Re: Full synthetic oil
Post by: Lon and Cheryl on May 24, 2025, 06:35:20 pm
I have run the T-6 for years and use it in everything. The M11, the generator, and the hydraulic system.
No issues.
Title: Re: Full synthetic oil
Post by: dans96u295ft on May 26, 2025, 09:50:58 am
I had the T-6 5-40 in stock for my pickup in the winter.
Title: Re: Full synthetic oil
Post by: Peter on May 26, 2025, 11:15:06 am
just an observation....To change over to full synthetic is would cost me just over 800 bucks Canadian for the oil alone. Amazon has the oil for 82 bucks CDN per gallon. My M11 holds 38 quarts.
Is synthetic really worth it?
Title: Re: Full synthetic oil
Post by: wolfe10 on May 26, 2025, 11:33:56 am
just an observation....To change over to full synthetic is would cost me just over 800 bucks Canadian for the oil alone. Amazon has the oil for 82 bucks CDN per gallon. My M11 holds 38 quarts.
Is synthetic really worth it?

IMO, NO. Dino oil in your engine, as long as changes annually/based on miles is fine.

Said another way, you will NEVER wear out your M11 because of using quality dino oil. Shell Rotella T or Delo 400 are very popular and quality dino oils.
Title: Re: Full synthetic oil
Post by: Peter on May 26, 2025, 11:49:51 am
thank you for the (less money!) explanation!
Peter
Title: Re: Full synthetic oil
Post by: John44 on May 26, 2025, 12:20:41 pm
Everyones money situation is different,for me the Amsoil is well worth it,with a bypass filter and their signature series oil I can
go 20k miles on a 8,3 with over 200k miles,engine never got over 205 degrees with the retarder,yes Brett is correct you will
never wear your engine out but it will run a little better with synthetic oil.If you need more info,contact John Haygarth,he is a
Amsoil user in Canada.
Title: Re: Full synthetic oil
Post by: dans96u295ft on May 26, 2025, 02:19:53 pm
I paid $19 a gallon 5 years ago
Title: Re: Full synthetic oil
Post by: Barry & Cindy on May 26, 2025, 08:27:05 pm
One of the benefits of changing engine oil is to get rid of contaminants, so most feel that it is fine to use better oils, but they do not necessarily extend oil change intervals.  This is not the same for transmissions, etc as better oils can extend the useful life.
Title: Re: Full synthetic oil
Post by: dans96u295ft on May 27, 2025, 12:20:28 am
I change oil at 5000 miles.
Title: Re: Full synthetic oil
Post by: John44 on May 27, 2025, 05:21:06 am
Reply to number 9,that's why some of us install a bypass filter,goes down to 1 micron and adds a couple of quarts to the system,
and no it does not effect oil level.