Switching over to Royal purple 15w40 engine oil tommaro. What is the recommended oil change interval? I usally run dino oil @ 5k change. Truck has 36k miles as of now. I do tow often. Thanks.

 

I've put 25k on RP with a bypass and the UOAs were still fine. Craig

 

Royal Purple dosen't have a recomended lite duty/heavy duty oil change guide on their site.www.Amsoil.com does with all their oils and most lubes.

 

Those using, what would you recommend is a "safe" interval?

 

I run Rotella 15,000 miles, I'd expect at least twice that to justify the cost.

 

Personally I run Royal purple with a wix filter 7500 miles, change the filter and go another 7500 miles and drain. Even then it is in good shape. It is certain that Royal purple can take 30,000 miles and more, its just finding a good filter to accompany it.

 

A bypass filter! Nobody can tell you for sure what's safe once you go past the oem recommendation. That's why there is UOA. Craig

 

sorry for asking the dum question but what is UOA? what filter would you guys recomend

 

Used Oil Analysis. You buy sample kits from CTC, Blackstone etc. and the price includes the testing. The last kits I bought from RP cost $7.50 but that was awhile ago. I think Scheaffers has a good price too. I bought an Oilguard bypass (and 20 elements) years ago for 1/2 price. Oil guard claims it's plenty safe to double the oem recommended OCI with their bypass. Frantz (TP filters) are the cheapest and work really good but the rolls have to be changed often. Amsoil has a good bypass but the filters are high. Craig

 

I believe when I get into higher mileage (150k+ miles) I will put a bypass on.