xcellent

hi guys, i been doing some research but couldn't find any experience on these oils called "Castrol Magnatec 5W-40 C3"

http://www.castrol.com/castrol/produ...tentId=7028389

does anyone have any experience with these? is it safe to go ahead and buy?

mine is 95 cherokee 4.0l

xcellent

maybe worth mentioning where i live the temperature various from winter/summer, -20'celcius(-4'fahrenheit) / 30'celcius(86' fahrenheit)

xjbuddy

how many miles does it have???. 5w40 sounds really thin of oil to be running in a jeep(its viscocity). maybe on one of those crappy *** 3.8L wranglers, but not in a 4.0L. if castrol makes it in a 10w30 or 10w40 weight then i would consider buying it. good luck, hope i helped a little.

xcellent

thanks... my xj has about 90,000miles... isnt 5W for the winter i.e. lower the better for winter? Thought it would be lower the better since i live in cold place, but please correct me if i m wrong!

arsxj

Thats thin. I would get some good 10W-30 and run it year round. You are correct you could run 5W-30 during the winter but once the engine is warm its still going to thin out.

djb383

5W40 is thicker than 5W30 at operating temp. Thicker oil is harder to pump, wastes horsepower, creates higher oil temps. Higher pressure does not equal better lubrication.........flow equals lubrication. Even 0W20 is too thick to adequately lubricate when cold but its about the thinnest available at present.

http://www.supramania.com/aehaas/

troy fritz

I run 10-30 in winter and 10-40 in summer . Have for years and never a problem.

xcellent

Thanks for your input... I bought Castrol Magnatec 10W-40 half/semi synthetic in the end... hope it goes smooth!! will let you guys know the outcome.