I do about 5000 on oil/oil filters, and 7500-10000 on fuel, closer to the 7500 though. I also use the truck as a sports car though.

The stock air filters last a pretty long time, and are one of the best filters you can buy.

 

we all forgot one of the most important questions when talking abou tfuel mileage////
WHAT GEAR RATIO DO YOU HAVE// 3.73 of 4.11 it does make a big difference

 

I have no idea what gears I have. Mike if that filter looks good should be fine right

 

1. If your speedo says 70 mph at 2000 rpm, you have 3.73s, it will be 22~2300 with 4.11s.
2. You can't go by how the filter looks, if you have accumulated the mileage, change it. I had a Ford filter that "looked good", a couple of taps on the shop floor revealed that it was full of sand. And I had just bought this from Jones West Ford in Reno!

Nobody wants to admit this, but because we must keep up on the maintenance of these trucks religously, I consider them high maintenance vehicles. But I'm cool with that.

 

My gpa Dully get 11 mpg at the most use to get 17. But I think the engine bout to take it last breath P.O.S 6 o's..180k and I can smell diesel in the oil and we change it every 3k but he doesnt always let it warm up...

 

I am pretty sure I have 4 11 then because I know I turn more than 2k at 70 I will make sure today

 

Hard to say man. These trucks do have a filter minder so it will set a light off on the dash or it will read "check air filter" when it sucks the filter minder in. I think the stock filters will hold POUNDS of dirt before needing replacement, actually quite impressive. Hard to tell by looking at it though.

The easiest way to check gear ratios short of pulling the cover... Put the rear end in the air in neutral (block the front so it can't roll). Spin the tire one full revolution, and count how many times the driveshaft spins. Put a mark on it and count it. If it spins just less than 4 turns, it's 3.73's, a little more than 4 turns and it's 4.10's.

If they've never been replaced you can pull the axle code from the door jamb and we can tell you what it has too. That's probably the easiest.

See above.



fuel in the oil is most likely from long idle time's, or bad o-rings. Hard to blame the truck on that. I doubt it's taking it's last breath at 180k, but any engine with that kind of mileage you can expect to do some sort of repair. They don't run on hopes and dreams.

Your nose (smelling diesel in oil) also isn't a very good indicator, how about spending the $25 to do an oil analysis and actually see what is going on instead of just pointing fingers.

His poor fuel mileage could be accounted for due to multiple things. If you want to start a thread about it we can probably help you narrow it down too.

 

Actually, the spin/count method is probably the best idea. 2000@70 mph assumes 2 things:1. that your converter is locked up properly 2. that the gears haven't been changed.

Don't these trucks have a tag on the diff showing r&p ratio? I don't remember if mine had one when I put that cool guy, extra capacity, polished, finned aluminum diff cover on.

 

Yes karl, they should. The doorjamb is easier to read though

 

any smoke or rough running mine was doing the same I replaced 2 injectors and the hpop and i am getting 20mpg highway now and my tires are 315x70x18