Oil to reduce consumption

Feb 24, 2009
Abingdon VA
I have a 2004 Silverado 5.3 engine with 200k miles. I have been running pennzoil platinum 5w30. But have been noticing it’s using over a quart in 3k miles. Would another brand oil maybe reduce consumption. Was thinking about trying valvoline syn or Castrol syn. It does leak some but not enough to mark the drive way.
you could try using a high mileage oil.

1qt in 3000 miles is not all that bad IMO.

In other words I don't think it warrants any sort of repair.

Couldnt hurt to try a high milage oil or even a thicker high mileage oil such as 10w40(at least in the non winter months.)
Pennzoil Platinum in 5w-30 specifically is on the thinner end for that grade, you might have a better experience with your consumption issue with M1, Valvoline, Castrol or any other Dexos1 Gen2 approved 5w-30.

HiMi oils also are usually a bit more viscous than their standard mileage counterparts and may also help both of the issues you're experiencing, but you might not find as much of a variety of HiMi 5w-30's that are D1G2 approved.
I use RGT 5w30 in mine and have to add maybe 1 qt between changes, I have an '04 GMC Sierra w/ 5.3 but only 116k miles, ever since Pennzoil changed the formulation to Pure Plus technology the consumption when using that oil has been greater which I've noticed when using it in my car but others have experienced the same results. If you don't want to try the RGT then check out Castrol Magnatec which is also Dexos rated. You can also try any HM oil but honestly I haven't seen where it helps all that much with consumption, I know Castrol HM is supposed the thickest within grade so that may help right there. When using HM oil in my car I can usually tell it's a bit on the heavy side when using the Castrol but with Pennzoil or Valvoline I can't even tell a difference.

You might want to look at an HDEO unless you want to stay with something that is Dexos rated.
My consumption went down when I switched to Red Line. My car does not consume any for the first 3000 miles now. After 3000, it starts to consume. I think as the oil ages and thins down, it starts to consume again. I use 0w20.
M1 5w30 EP HM reduced my consumption (even vs M1 0w40). Pennzoil was a joke when it came to consumption in my VQ. It burnt like crazy.
The oil that really slowed down consumption in my daughter's Kia is Supertech High Mileage Full Syn. I went with a 10W-30, which is the thickest allowed in the manual. It slowed it down a ton, and it’s cheap!
I'm replacing the defective valve cover on my 2005 this weekend. Mine uses a bit of oil but also used to smoke on startup in the morning sometimes....until I installed a catch can. Now it only smokes if I let the catch can overfill. As per a GM TSB the drivers valve cover needs to be replaced. It's a fixed orifice pcv so no valve to change.
It's gotten worse to the point that 150 miles of driving will fill the can and it will smoke the next morning if the can was full to the top. I got a leakdown test and the worst cylinder was about 12%, the rest 5-6%, so engine blowby isn't a problem.
If you've ever seen smoke on startup then this is likely the problem. It's much more common than valve seals which is what I originally suspected until doing some research and installing the catch can to prove it.
I would switch brands.

I have experienced oil consumption with Pennzoil Platinum 5w-30 and Ultra Platinum 5W-30 ever since they went to the PurePlus GTL formulation. I don’t think it’s because of it being on the thin side for the grade either. In multiple vehicles I have experienced oil consumption with PP and PUP 5W-30. FWIW, one of my vehicles the owners manual allows for 5W-20 and 5W-30. I can run whatever brand 5W-20 and there is no oil consumption. Switching to PP/PUP 5W-30 and it starts consuming oil. So I believe it has something to do with the base oil chemistry, rather than the viscosity.

My other vehicles call for 5W-30 and that’s all I use in those. I can use whatever brand 5W-30 with no consumption. Switch to PP/PUP 5W-30 and they start consuming oil.