TCinNH

I just bought a slightly used 2003 F150 Supercrew, 5.4L. The oil fill cap says to use 5W-20 oil. Are the tolerances in these new engines good enough to allow the use of such light oil? I tow a large snowmobile trailer during the winter and a boat all summer. Is this oil going to stand up to this type of driving, or should I go with a higher viscosity?
TonyC

ModMech

While the 5W-20 rating is mostly for CAFE, to answer your question, YES it's enough and NO you should not use a heavier wt oil (although you *could*.

pete54ford

I myself would go higher. But then again thats just me. And a little about myself...I put Motorcraft in my wife's 2001 Alero, I tried to get her to buy a Ford, but you guys know women! LOL

gdavis1

I have read in another forum that if you use heaver weight oil than recommended you run the chance of starving the engine of oil. Reason was give the oil jurnals or ports are small therefore oil flow is resticted and the oil pump pumps the oil faster than being returned. I have decided to go with recommended oil and change every 3k miles

ModMech

The reason, aside from CAFE, for lighter oil is twofold. First you do not need oil any thincker to get the required protection, and secondly the oil feed passages to the heads are relatively small, and long. In cold weather, you WILL starve the cams of lubrication during and after a cold start with 10W40/15W-40 oils, and possibally with 10W30.

urban cowboy

Yep, that oil is right. Ihave the 250 Super Duty with the V10, which calls for the same oil. I work the hell out of it, constantly pulling heavy loads. At 60,000 miles in little over a year, it still runs like the day I bought it!

yotermanic

I didn't believe in 5-20 until I was at a dealership. Now I see some of my regulars (people in every two weeks for an oil change) with 300,000 miles on their trucks. I guess Ford pays a lot more people who are a lot smarter than me to figure this stuff out. I'm a believer now!

timex129

The biggest mistake when it comes to oil, people think they know that the W stands for weight. The W actually stands for Winter

catback23

Ah just what I was thinking after I read your post. W does not stand for winter.