5w40 vs 5w50

[Tedybear]

Ok, here's a good one.

Our local Advance has a buy one get one deal running on Castrol Edge full syn. oil.

During the winter months I normally run 5w40 full syn oil. The engine seems to love it. I tried 5w30---but the oil guage kept twitching. (Yes I know...the bearings are very weak) Normally in the summer time I change out to 10w40 syn. oil As the hotter temps and this makes for a good combination.

Now I do understand the first number is the weight of the oil when at a set cold temp. Would 5w40 be just as thick or thin as a 5w50? We are getting down to some pretty wicked cold temps--and I need to invest in some extra syn oil. (the engine does not burn any oil---but it still has two oil leaks)

Just want to see if the 5w50 would work well along the 5w40.

To answer the expected questions: We tried to run the engine with 10w30 and 10w40 in the colder months. It sounded like someone filled a can with marbles when it started. We changed it back to 5w40? And it was about 85% quieter due to the oil getting to everything faster.

The sale ends soon, and I need to get some feedback. NOT on Dino oil VS Full Synthetic....we've run that debate until it's been beaten. Just the pros and cons of using 5w40 vs 5w50 full synthetic.

The current oil we use is 5w40 Diesel engine oil full synthetic. The engine seems to love it. I have to get as much life out of this engine as possible, and I know the causes of weak oil pressure/volume. Yes the engine has severe wear, and worn cam bearings. It however does not burn any oil, and runs fairly well--even not to loud according to the ford techs at the local dealership. I just need to nurse it along as long as possible.

Thanks!

S-

 

[adsm08]

5w40 and 5w50 would be the same at ambient temp, the 50 will be thicker with the engine at temp since the second number rates the thickness of the oil around 212*F.

That diesel oil is good stuff though, keeps things nice and clean.

 

[Tedybear]

5w40 and 5w50 would be the same at ambient temp, the 50 will be thicker with the engine at temp since the second number rates the thickness of the oil around 212*F.

That diesel oil is good stuff though, keeps things nice and clean.

At this rate? I think to extend what life is left of the engine? I'll probably start using the 5w50 at next change. I need to rebuild it---or at the least new bearings. Can't do much until I get a garage area again. The barn we where using? No insulation, No heat...and the cows are quite...hummm....

I'll need the mask at this point....

I've had people actually argue with me about using diesel oil in a gas engine. It's when I point to the rating on the back--and it's the same UPI rating as the oil they swear by. LOL

Have a good night! This head cold is kicking my arse tonight.

S-