I'm about a quart low after 3000 miles. Is this about normal at 100k miles? There are no visible leaks on the outside of the engine and absolutely no blue smoke.

 

To make blue smoke it has to be plenty of oil to be burned. One quart is not so bad for a high mileage but that is never good. Just keep an eye on it. If it starts loosing more you may want to rebuild.

 

So my 2 qts in 3000mi is pretty horrid lol.

Check your plugs, i have an oil leak in one of my cylinders. The plug was COATED after a routine maintenance. not the present i was looking for...

 

I changed my plugs a few thousand miles ago and they looked great.

 

Damn, my 4.7 doesn't even use 1/4 quart for 5000 miles. Well, maybe 1/4 quart at 5 k...

My Shadow on the other hand uses a quart every 3k, but it leaks like a sieve.

 

Haha at least your trucks aren't using 1 quart every 140KM.. I had a S10 that did that lol

 

I have over 250,000 on my 3.9 magnum and when i bought it new i got a courtesy card from the dealer for a lifetime oil change and inspection there, and to this day with nothing more replaced but an air conditioner compressor,water pump and an alternator i have not one drop of oil under my truck and no oil burning problems.I cant say enough about how good of a truck this one is since i follow and write down all the matenence intervals since i bought it new in 2000.