djsf150

I am going to beat this oil subject dead horse some more. I have an 04 F150 fx4 (5.4) and the manual says to use 5w20. I am moving from Michigan to the desert in California and temps can get over 100 degrees in the summer. I am running Mobil 1 5w20 full synthetic. Does anyone think this oil would be to thin for that kind of heat? The easy answer is run 5w30 in the summer than. But ...
I guess I am just looking for some opinions.

NCSHP311

Is that a Ford recommendation for your region? If that is what is used in all F-150's then I dont think it would be too much of a problem. I have been told the weight of the oil only really matters at start up as the heat will thin it out anyway.

Octane

5w-20 will work fine even in 100 degree temps. If Ford says to use 5w-20, thats what I would do.

blackbetty

i live in socal and the desert is my second home, i run only mobil 1 5w20

djsf150

Ford recommends the 5w20. I will stick with it, but in full synthetic.

Evil Eyes in Pendelton or Mirimar?

GtRugby90

5w-20 Royal Purple is my recommendation. I have run the the full synthetic Mobile-1 and it wasn't bad, but full synthetic Royal Purple blows anything else out of the water.

transmaster

I was going to change my oil out to Royal Purple but I went with Castrol Syntec instead which was just short of $1.50 per quart cheaper. The owner's manual for my truck shows 5W20, or 5W30 is the specified oil. I chickened out and put 10W30 in it instead. I see the EPA ratings for gas mileage for my truck with the 5.0L V8 has a range of 15 city, and 20 highway and this was obtained with 5W20 weight oil. One of the reasons why I went with Castrol Syntex is it is easy to find. In Cheyenne the only place that actually stocks it is Advanced Autoparts, and it is over $7 dollars a quart.

GtRugby90

this sounds ridiculous, but I actually get better mileage with the Royal Purple than with any of my other previous lubricants. If you don't believe me go to their website. TRUCKS! the television show did an evaluation of this claim and proved it to be true - they even have dyno sheets and other valid documents to prove the statements of Royal Purple users.

transmaster

I saw the same thing, and I still want to change over to Royal Purple. With Fuel so expensive anything that would save gasoline would pay off.

djsf150

How much did you pay for a quart of Royal Purple? I pay about $6/qt for Modil 1. What change interval do you run the Royal Purple for?
Anyone ever try Amsoil? I used to have a 4runner and everyone in that community swore by it. To expensive for me though. I think it was over $10/qt.