Bugman: I too have heard the neg comments about rotella. A friend of mine did some tests with it and he too came to the same conclusion: and that is that Rotella tends to foam when you extend the oil usage to over 3k miles. So if you have to use Rotella, change it out every 3kmiles and you shouldn't have any problems. I use CAT full synthetic oil and CAT oil filter in my truck. This oil is packaged by CAT but is actually Delvac 1, a highly rated oil for our engines. Some have had trouble finding Delvac 1 and if you decide to run this oil, then you can look in your area for a CAT heavy equipment dealer and call their parts dept. My CAT dealer didn't carry this oil but would order it for me from their main headquarters. I'm running this oil for 10k miles and doing oil filter changes at the 3k and 6k mark. Also at the 3 & 6k mark, I have an oil sample pulled and sent to CAT labs for analysis. At the 10k mark, all oil is dumped and changed and another new oil filter is added. I do not have an oil by-pass filter at this time but I'm looking into it. (haven't convienced my husband that oil should/can stay in for more than 10k miles) Before I changed to synthetic oil, I ran CAT diesel oil. Changed it every 3k miles.

 

Tina,
One of my main reasons for buying a diesel was to go 4,000 to 6,000 miles between oil changes. In my business, I can easily go 3,500 to 4,500 miles per month. I was getting tired of doing oil changes every month. So, I'd figured by purchasing a diesel I could extend my oil changes. I checked the ford diesel website and saw that they too recommended the Shell Rotella T engine oil. I will take your advice and switch to the synthetic motor oil in a few months. I still have some Shell oil and I also have 5 gallons of the Valvoline fleet oil to use up first. Also, what kind of fuel additive do you use for the winter?? Up here in New Jersey, most of the fuel stations have the winter blend diesel fuel year round. Also, what kind of fuel mileage do you get with your diesel?? Thanks. Bugman.