And I shudder thinking about what could happen using oil that thin. There is no reason to use 5w20, Ford just started using it cause it is slightly thinner and gives them a mileage increase of about 1.

 

Yeah, try running 20W50 in a Triton engine, and then try to get warranty coverage if or when it breaks. They're designed for that viscosity, otherwise they wouldn't specify it.,,,,98

 

I have also seen it proven that thicker oils rob HP, no reason to use it.

 

I've been working with a company that runs Ford vans on routes of 300 to 550 miles per day. Vans have 150000 to ~375000 miles. Run every day, oil changed ABOUT 6000 miles, oil used is Advance Auto Parts 5W-20. Seems to me like the 5W-20 oil, and Ford engines are pretty good. (Engines used are 6 cyl. 5.4, & 4.6 ) One 4.6 blew @ about 380,000, another has about the same mileage and is still going strong, others in the 200,000 mile range. 'nuff said!

Please excuse if this is a dupe post!

 

I own a 97 4x with 165000 miles on it. I've had it for 4 years now and bought it when it had 70K. I take this baby hunting or fishing everyweekend and put it through absolute hell. It's also seen a lot of city miles too. no probs. (knockin on wood) Basic maintenance done using 5W30 Valvoline every 3000 or so. Hell, I just pulled an o4 duramax out of a muddy beanfield a few weeks ago. That felt great!

 

Some info you may not know about the truck versions of the 4.6L. The first thing you should know is that the car 4.6L (crown vic) version you see smoking at idle is not at all the same as the truck version.

The truck engine uses full floating pistons/pins. This means the pistons are totally different and much tougher than the crown vic engines. The truck version also does not use the low tension piston rings that cause so many problems on the crown vics. There are also a number of other upgrades aimed at durability.

The valve guide seals tend to harden and seep a little oil when outside temperatures get low. This results in slight seal shrinking and some oil gets by. The result is an intermittent puff of oil smoke upon startup. Keep this in mind as the miles pile on. It does not reflect the internal wear state of the engine. My truck has done this since about 50K miles. I now have 160K. My engine has just recently started needing 1 quart of oil at the 4000 mile mark (5K change interval).

FYI, the best 4.6L delivery truck versions used in fleet service have now reached the 900,000 mile mark with the use of synthetic oil. These engines typically last longer due to 24 hour service.

Chris

 

170,450+ Miles. I supercharged it last July. I intended to blow this engine and then install a forged longblock. Problem is this engine is not ready to give up. I get into 9-10lbs boost daily and tow a 4100+ lb 5th wheel trailer. This is the best engine I have ever had.
Just as a side note, I use synthetics exclusively.

 

WLF? Hmmm, 9 years old? You must have been one of the first buyers when they hit the dealers in January 96? I was working at a Pittsburgh dealer when they started showing up. I had no idea that a few years later I would own one. ,,,,98

 

98SCREAMER,
I'm just a couple of months short of the 9 years. Purchased it in the summer of 96. Had to have it shipped in from a dealer in Baltimore because there just wasn't any around. I remember it was the best looking truck I had ever seen and I had to have one. For the first 9 months there were so few that if you saw someone with one you would wave to them.
It has been a good truck and I have run it hard...

 

Mine has been cracked open once for a leaky timing cover gasket at 32k, other than that not much to speak of. Maintenance parts, and an alternator. I run mine hard too, but never got around to the supercharger. Nothing like buying a trouble free truck, I'm scared to buy a new one, which we were/are going to this Summer.,,,,98

 

I just can't justify a new one. Mine still looks and runs good.
It has a new transmission and a new engine is not that expensive; equal to just a few payments on a new truck...

 

148K and runs great. The most dependable engine I've owned (had a 4v in a '95 Mk VIII and it had 167K when I traded it on this truck). I'm thinking about a 4.6L crate engine and trans change if these wear out

Really like the truck; I usually get 24mpg on the hwy at 65mph!

Curt

 

Mine has 205,000+ and is still a strong puller and runs awesome.

I've got a head gasket that's seeping Eng Oil that I need to fix but for the time being I'll just keep toping it off every 1000 miles or so.

Doug

 

120,++ 4.6 on a 99 4x4 orig. owner never better superchip,airaid,poweraid,flowmaster.w/355 l/s A GREAT TRUCK.M.W.

 

'98 with 150k, runs great, very minimal if any maintenance done on the engine other than dino oil every 4,000 - 5,000 miles, pulled a plug out once and it looked great so didn't mess with changing them.

slight oil leak on one of the lines going to the filter, piston slap at 1700-1800 rpm which is gradually getting worse.