5W-20 in pushrod (OHV) motors

[Brett Miller]

Most modern engines do have roller lifters but do not have roller rocker arms.

 

[Steve S]

Why would there be less wear with xw/20 over a 10w30? What would be the expected m.p.g. increase? Can this be proven?" real life numbers?

 

[Brett Miller]

An important aspect is increased oil flow/volume with th xw-20 oils. I remember Terry discussing that awhile ago.

 

[G-MAN]

quote:

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Originally posted by Blue99:
The HTHS of 5W-20 oils generally runs 2.6 versus the 3.0/3.1 for 5w30's and I think this is the main issue for proper lubrication of the sliding friction components in a push rod valve train.

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I don't know of any modern pushrod engines that don't use roller lifters. The switch to roller lifters was chiefly motivated by CAFE and the move to 5w30 over 20 years ago.

 

[JohnnyO]

quote:

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Originally posted by Gary Allan:
You'll get lots of opinions on either side of the fence. The only way to know for your usage is to do a UOA at your normal interval.

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My wife's '03 Taurus has a 3.0 Vulcan (OHV) which gives nice UOA's on M1 and Motorcraft 5w-20. I used to have a '99 Ranger with the same engine that was spec'd for 5w30 at the time.
At some point this week I'll drain out the Pennzoil Platinum 5w-20 (first I've tried it) and get a UOA.
I'm going to refill with Pennz Plat 5w30 and get a UOA to see how it compares.