using a straight 50 weight

[The motor guy]

I know a guy who works in an industrial field and works with pumps and such. He uses a straight 50 weight in his truck. Down here in the south I guess you could get away with it, but he's an older gentlemen and I'm sure he was around before they came out with multi weight oils. He tells me a 30 weight is about as thin as you ever want to go. Opinions? I didn't have time to go into detail about it. Opinions? I believe the last time I talked to him about this is he likes that the thicker oil won't run off the parts as easily after shutdown as a thinner oil would.

Believe it or not I read an article about a guy who did a test like this about cold start noise problems and he had lots of noise with thinner oils 5w20 vs a 20w50. He claimed the same thing. The thin oil ran off the parts when the engine was hot from driving, then made noise waiting for oil to get back onto the internal parts in the morning on a cold start.

 

[Shannow]

what sort of truck ?

 

[The motor guy]

Originally Posted By: Shannow
what sort of truck ?


V10 dodge. I'm pretty sure it calls for 5w30

 

[Kuato]

Houston, where 40°F is really cold? Yeah he is probably good to go. Wouldn't be smart to do that during a Minnesota winter.

 

[DoubleWasp]

I'm running SAE 60 in one of my Chevy engined trucks. He'll be fine with that 50.

 

[Alex_V]

In 100+ temps straight 50 weight might not hurt a truck engine like that, but I doubt he'd see any negative change over the lifetime of the truck by using a good 10w30.

A good friend has an '01? Chevy K2500 (6.0) that he bought new and has used SAE 30 in its whole 200-some-odd thousand miles, and it purrs like a kitten. Wouldn't do it in mine but I guess it hasn't hurt it too much!

 

[Dallas69]

Most engines are very forgiving and seeing he is in Houston it might be OK.
He is better off reading his owners manual.

 

[Bamaro]

Seems like an automotive straight 50 would be difficult to find and I would be concerned with the additives, or lack of them.

 

[Chris142]

Originally Posted By: Bamaro
Seems like an automotive straight 50 would be difficult to find and I would be concerned with the additives, or lack of them.
valvoline makes it in both "sn" and a racing oil. Napa has it in napa brand and most other stores have it in racing.

 

[ShotGun429]

Probably wont hurt his truck, but 20w-50 would be a great option, I bet his bearings look great, run 20w-50 here in our Speed shop trucks never a failure of any sorts. .Years of dyno time here can confirm this.

 

[tig1]

Using a straight 50wt oil will slow the oil flow to the upper end, especially in cooler temps, will not decrease engine wear and may increase wear, will likely cause higher oil temps, harder on the starter, oil pump, and battery, and reduce engine performance. With that said, if your engine is already badly worn and you can't have it replaced, then perhaps a 50wt oil would be helpful.

 

[4WD]

My once nice yard is proof we freeze in the Houston area - why go beyond 15w40

 

[BrocLuno]

Originally Posted By: ShotGun429
Probably wont hurt his truck, but 20w-50 would be a great option, I bet his bearings look great, run 20w-50 here in our Speed shop trucks never a failure of any sorts. .Years of dyno time here can confirm this.


Yeah, I'd talk him into 20W-50 and let him get used to that. Then he can climb down to that watery stuff (15W-40) and he'll think he's in the thin crowd

 

[aquariuscsm]

Originally Posted By: 4WD
My once nice yard is proof we freeze in the Houston area - why go beyond 15w40


I remember Houston getting ice maybe three years ago,and Brownsville-Port Isabel-South Padre Island area getting snow.

 

[JimPghPA]

I once read an internet post where someones kid filled a snow-blower with straight 40 weight and the engine blew the connecting rod through the side of the block.

While a straight 50 weight might work in an engine in the temperatures seen in Texas, there is a limit to how low of a temperature a straight 50 weight oil will work well enough to not cause an engine to blow up, and the winters north of Texas probably get plenty cold enough to cause an engine using straight 50 weight to blow up during a cold start.

 

[Johnny2Bad]

For nearly a century air-cooled motorcycles (including 3-wheel and sidecar-equipped versions that can and do run in sub-zero weather) and piston aircraft specified SAE Grade 50 oil * and that recommendation hasn't changed with the advent of multigrade motorcycle and aviation oils for those particular engines that originally called for straight grade oils, and they don't "blow up" as a result of their use.

Aircraft in particular here in Canada often start in extreme cold weather. Although many such motors use main roller bearings not all do, and it doesn't seem to make any difference.

It's not what I would run or recommend, but I don't think he's risking catastrophic failure.

* Aviation 100 which is equal to SAE 50

 

[gfh77665]

Originally Posted By: aquariuscsm
Originally Posted By: 4WD
My once nice yard is proof we freeze in the Houston area - why go beyond 15w40


I remember Houston getting ice maybe three years ago,and Brownsville-Port Isabel-South Padre Island area getting snow.


Yes it was a basically a one day freak event. Even then the temps were about 30 or 31 degrees, and then right back to the 60's or 70's afterwards. Of course a straight 50 wt. is still not the best choice, but it won't be catastrophic either. If someone was determined to run a 50 for some reason, why not use a 20w-50?

 

[Garak]

Originally Posted By: Johnny2Bad
Aircraft in particular here in Canada often start in extreme cold weather. Although many such motors use main roller bearings not all do, and it doesn't seem to make any difference.

Of course, they've taken precautions in this province over the years, up to and including using a fire to heat the sump contents.