Are there any modern non OHC engines spec'd for 5W20 yearround? I was considering running 5W-20 in my GM 3.8L since I do 2-3 mile trips most of the time to school and it would flow better, but once on the highway I wonder if it would be of any benefit or harm in a non OHC motor.
5W-20 in pushrod (OHV) motors
- Thread starter Dominic
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I believe the 3.0 Vulcan, in later Ford models, spec's 5w-20. I use it in my daughter's 91 Taurus without a worry.
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.
I'd use it just because you infer that your primary usage is short trip. This is the ideal, commonly available, oil for that situation. It's probably still a 40 weight when you shut the key off ..probably higher
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.
I'd use it just because you infer that your primary usage is short trip. This is the ideal, commonly available, oil for that situation. It's probably still a 40 weight when you shut the key off ..probably higher
The Sequence IIIG engine test uses a GM 3.8L V6 modified with a flat-tappet lifters (pre-'86?) configuration.
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GM originally spec'd 10w30 in the 3.8 (even when most of their other motors were calling for 5w30). Does this mean that the 3.8 prefers a more viscous oil? I don't know either.
I am all for 5w20 in motors that spec it but I think I'd stick with what the manufacturer calls for.
I am all for 5w20 in motors that spec it but I think I'd stick with what the manufacturer calls for.
Doesn't the "Hemi" specify 5w20? It's definitely a pushrod (OHV).
The 2002 and later Ford truck 4.2 V6's are speced for the 5w20. They are an OHV pushrod engine.
I was using 0w30 in a Buick 3.8 with excellent results.
I was using 0w30 in a Buick 3.8 with excellent results.
If you pour that oil into your engine it will get very dark inside of it when you replace the oil cap.
Otherwise it sounds like a worthy experiment.
Otherwise it sounds like a worthy experiment.
I run Motorcraft 5W-20 in my Ford 3.9L Freestar.
I have a '96 3.8L windstar.
Original oil that was listed in the owner's manual is 5w30.
FORD issued a TSB that states that 5W-20 is Approved for my engine.
You don't list the year for your car.
If you have an older vehicle, like I do, you could check to see if there is a TSB that updates what is printed in the owner's manual.
Original oil that was listed in the owner's manual is 5w30.
FORD issued a TSB that states that 5W-20 is Approved for my engine.
You don't list the year for your car.
If you have an older vehicle, like I do, you could check to see if there is a TSB that updates what is printed in the owner's manual.
My Ranger's 3.0 Vulvan has seen mostly 5w20 Castrol and Motorcraft for its 55,000 miles. It does show a bit high in lead on UOA's, but nothing to keep me up at night. That said, I'd stick with 5w30 or 10w30 for a GM pushrod. If it ain't broke, don't fix it.
Well with frequent trips, the problem is not flow; the problem is water that gets in the oil from condensation.
Frequent oil changes would be the best bet.
I own a Taurus 2001, we use the 5W20. But because that is what is recomended for this engine.
I wouldn't without the ok from GM.
Best bet would be to email somebody at GM, or call them.
Otherwise, if it's lots of short trips, just change it every 3 months.
What oil are you currently using?
Frequent oil changes would be the best bet.
I own a Taurus 2001, we use the 5W20. But because that is what is recomended for this engine.
I wouldn't without the ok from GM.
Best bet would be to email somebody at GM, or call them.
Otherwise, if it's lots of short trips, just change it every 3 months.
What oil are you currently using?
2002 Chevrolet 3.8L (Buick 3800) Pushrod OHV V6
42000 solid miles, no leaks, no oil consumption, runs like a top, and she pulls 14.7 in the 1/4 mile on pump 87 and gets 29-31mpg on the highway. The reason for attempting 5W-20 is twofold:
1. Decrease wear on 2-5mile trips, but what happens on 15-20mile trips when the oil is fully heated and is thinner than the spec'd 30? Do I get increased wear perhaps? I do drive spiritedly.
2. Increase fuel economy on 2-5mi trips. Im sure a thinner more fluid oil would lubricate better cold than my 5w30, but when hot I worry. This is why I run 5w30 (spec'd for 10W30) now instead.
The hemi point was a good one.
When starting the vehicle the viscosity could be 150cst or greater in moderate temps(55-100cst @100°f). Then it is reduced to around 10.5cts at operating temperature for a 30wt and ~9cst for a 20wt after that huge viscosity swing from cold to hot 2cst or less is not going to be very influencial on your wear. Indeed the time it takes the oil to go from too thick to operating viscosity is more important than the final viscosity in terms of wear(too thick is worst than too thin). Read Dr. HAAS's papers. They make good sense.
The note of "increased lead" goes with the recommendation on how to "select the proper oil weight" from a new-to-me oil line-up with a fancy race circle's name, referencing only bearing clearences of the crank (assuming mains and conn. rod's big end). Pushrod/OHV or OHC arrangements not considered IIRC, perhaps because of focus on it's intended market in official racing.
Nothing new I suppose,...trend UOA's to learn your engine's specific needs if you are so concerned and dependent. The expression, "Same but different," is applicable here.
Nothing new I suppose,...trend UOA's to learn your engine's specific needs if you are so concerned and dependent. The expression, "Same but different," is applicable here.
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.
Also, for 6 months out of the year, in the Philadelphia, PA climate, the fuel economy gains of a 5W-20 vs. a 5w30 will be in the 1% or less range & very tough to measure.
Also, for 6 months out of the year, in the Philadelphia, PA climate, the fuel economy gains of a 5W-20 vs. a 5w30 will be in the 1% or less range & very tough to measure.
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