my 03 sedan auto has been using 1 qt of oil for every 3,000-4,000 mile oil change. It's been the same for 50,000 miles I've been driving it. Always used either 5w30 dino or synthetic. Mobil 1, Castrol, Penzoil Plat doesn't matter. Now in order to try to get this usage down, I want to try a different weight.
My first guess would be a 10w 30. or a 5w40 or a 10w40.

The question would be when is most of the oil being used? ie.. during when the motor is cold-warmed up? After it's warmed up? Or perhaps the valve stem seals are leaking a bit?

If it's burning it when cold, then a thicker W weight would be best. If it's using it when warm, then trying a 40 would be the next step.

If it's the valve stem seals, then I guess it's getting burnt all the time and perhaps I need an oil that will swell the seals a touch? Recommendations?

 

If the motor is burning oil changing brands or viscosity will not fix it. Worn piston rings, head gasket must be repaired.

 

Is there any smoke or essence of burning oil? It could be as simple as a damaged pcv valve. If its damaged it can allow for excess oil vapor to be recirculated into the intake plenum. Over time this would definitely cause a depletion in oil level. As Davidv stated.....you are likely going to have be proactive in replacing some things to remedy the issue. The pcv is a very inexpensive (and easily replaced) to do. I would try that first. Perhaps remove the plenum and see it there is an excess of oil deposits in the lower plenum. Just my .02, and good luck.

 

Ah PCV is a good idea. I hope it's something like that. When I did my crawford, I didn't notice any excessive oil in the plenum though.

David, what does the head gasket have to do with anything? It could be worn rings but I don't know. A thicker oil would help slightly in that regard if it were.

 

that's really not burning anything a quart in 3000 miles is good. I wish i only burned a quart in 3000 i used about 1/2 quart to whole quart every 1000 on my 2003

 

no bueno.

 

Check your PCV valve it could be stuck open or clogged, also check you spark plugs to see if there is any oil on them. also check your Valve cover, that could be leaking as well.

the 02-03 6 speed VQ35's always seem to have this issue, its fairly common on the earlier gen VQ35's, specifically the DE. Edit: it appears the HR/Rev-up has the same issue as the DE.