High milage engine oiil weight recomendation.

[CaptainFreon]

2003 Ford E350 super duty. 331K miles. Been running NAPA Synthetic 5w-20 (weight noted on fill cap). I add about 6 quarts every 5K miles. What weight should I increase it to?
Work truck, loaded with weight. It's been driven well, not abused, I bought it new.
I want to stick with NAPA synthetic. All those miles and still running great! never blew a plug or lost a timing chain.
thank you in advance.

 

[Alex_V]

Which engine? Certainly go up to a 5w30, and a 10w30 probably wouldn't hurt. I've seen sale flyers with a red bottle Napa high mileage oil advertised but I've never seen any at my local store.

 

[Audios]

Alex is right, maybe 5 30 winters and 10 30 summers. See what burns the least amount over the interval, youre using it often so wont take long to see the difference.

 

[SilverFusion2010]

10w-30

 

[Seventh]

I'm guessing it's the 6.8l V10

Bump it up to 5w 30 and see how much, if any, the oil consumption is reduced.

That motor probably wouldn't complain about a 40wt either, but take the scientific approach and do a 5w 30 first me thinks...

 

[Rolla07]

10w40 HM.

 

[TexasVaquero]

Do as the guy recommeding 5w30 and 10w30. Also, maybe even 0w40

 

[901Memphis]

Maxlife 5w30

 

[CaptainFreon]

5.4L

 

[Red91]

Six quarts in 5,000 miles is unusually high, especially for a mod engine. By any chance is oil leaking from the head gaskets? I've seen this happen on a couple of E series vans.

 

[BrocLuno]

With that mileage, I'd say the bearings have opened up enough to just switch to an HDEO. Rings are worn, the valve guides too. Shell Rotella 5W-40 and see how it goes ...

 

[L_Sludger]

Why won't you just try to stay in the same viscosity, but try a different oil? I heard MaxLife Synthetic is pretty nice for older engines. Why not try that for a couple of intervals to see if it helps at all?

 

[FCD]

Switch to Mobil 1 HM 10W-30 or Shell Rotella 5W-40

 

[Dallas69]

5-20 maybe OK for a new engine but not for 330k.
Move up to 10-30 and see if it helps. I would use a HM oil also.

 

[HerrStig]

For the summer I'd use 10 W 30 Maxlife synthetic. IF that helps try 10 W 40.

 

[addyguy]

6 quarts in 5k is getting up there for consumption. I'd move to a 40-weight for sure; either a 10W-40 HM oil, or any 15W-40 oil to see what it does.

 

[Red91]

If the OP wants to stay with Napa oil, their 15W-40 can be had on sale for several times a year at $8.99-$9.99/gallon. Dare I say I'd try a combo of 15W-40 with a quart of Lucas? I'm not the biggest fan of it, but it has slowed consumption and/or quieted noisy bottoms ends on several customer's vehicles who just want to nurse their cars along as long as they can.

I'd try a straight 30wt by itself first. With the quoted consumption, you're not going to hurt anything whatever you decide.

 

[Dallas69]

Don't ever use Lucas.

 

[SilverFusion2010]

Oil additives are almost universally bad. If you want thicker oil go up to 20w-50