I guess to make this question short...is it overkill to put in 10W-40 in a 01 4.6 if I m going to be running her rather hard, in the desert this summer?


need your experienced help, so that I can plan ahead!

Thanks.

 

10w -40 is becoming an obsolete oil. One of the problems with it, is it takes much more polymers in the oil to create such a wide spread in viscosity (10 weight to a 40 weight) and is more prone to breakdown. You would be better off with a good quality 5w-30 or 10w-30. If it is going to be extreme, then I would suggest going with a synthetic, such as Mobil 1.

 

Right on Navi ! I always trust your opinion on these matters.

I'm taking a trip to New Mexico this summer, so I'll expect it to be pretty warm in the day...cold in the evening. I'll stick with 10W-30 during the trip, then.


Best,

Matt

 

I've lived in middle of the mojave desert for the past 5 years now and run a synthetic 5W-30 in all my vehicles with no problems. When it gets up to 120 degrees and you can sit and idle for 10 minutes without overheating I'd say everything is working allright.

 

We don't use 10-40 here and we get over 100 - 100* days, heh

 

HI!... Actually thicker viscosity oil like 10-W-30 or 40 will break down less in extreme conditions such as drag racing. They will also actually create more oil pressure vs. a less thicker oil. I run 20-w-50 VALVOLINE in my 408 race engine in my RANGER. Everybody I know that races at the dragstrip runs 20-W-50 in their PRO STREET drag cars. On my F-150 I picked up 15PSI oil pressure when switching to 10-W-40 vs. the **** water factory oil. Also my piston slap noise almost vanished. I also noticed that when I ran the factory 5-W-30 that when I did oil changes every 3500KMS that the oil was extremely black and like **** water. With the 10-W-30/40 it keeps it's viscosity and is slightly dark brown when being changed. Sorry but I'll stick to my heavier viscosity oils in my vehicles. We all know how hard I am on my F-150 and I hav'nt had any problems yet concerning oil choices.

 

Neal - is the "BS" about Tighter tolerances in the Mod motors just that - "BS" or is there some truth to it. And does the 5w-30 and 5w-20 now recommended just provide less resistance for better MPG numbers for the company as a whole not anything to do with protection?

sorry for rambling

 

HI!... DoggieDoc No it is not B.S. The new modular engines have extremely tight tolerences. FORD no longer uses "THOUSANTHS" when specing engine parts. They are now using "MICRONS". Yes the thinner weight oil is just so FORD's can get their FLEET MPG rating, nothing more. Just for your info, about 15 years ago a brand new engine would take only about 2500 miles to totally break in. These new modular engine take almost 10,000 miles to totally loosen up. Just ask the LIGHTNING guys. The more miles they are putting on their trucks from new the faster the trucks were going in the 1/4 mile...... to an extent.

 

Neal~

I think I'm going to stick with the 10W-30 for the time being. I share your point of view with the higher viscocity oils, and I feel that the higher weight oils are important for high performance vehicles, such as your trucks. So, thanks for your imput. I feel better with the decision to stay with 10W-30 during the warmer months.

Thanks to all who have replied!