5-30 synthetic in an H ?

riverbend · Dec 4, 2009

The manual calls for 10 weight oil below 32F, and I'm wondering if 5-30 synthetic is too light for my H. It's due for a change and I have always used 15W40 year round in the past.

It is getting colder, 10F this morning, and I'll be using the tractor all winter. This is just a work a day H. I went through the motor about 5 years ago and the oil pressure (with 15W40) is right at the top of the gauge.

What do you think ?

Thanks

Greg

rustyfarmall · Dec 4, 2009

Stay with the 15w-40. The recommendations given in the owners manual were based on the motor oils available way back then. If that H Farmall was being manufactured today, I'm sure the owners manual would recommend the currently available, modern, multi-weight oils, most likely the 15w-40.

Andrew Z · Dec 4, 2009

i would stay with the 15w-40. the 5w-30 stuff is very thin and youll likely start "using" oil. the tolerances in these engines are quite large compared to new modern engines that 5w-30 syn. was developed to run in. just my thought but stick with the 15w-40 a strong battery, and properly tuned engine and youll be good to go.

Andrew

Mike CA · Dec 4, 2009

From what I've read over the years on this forum, the 15w40 has zinc in it, which modern cars don't need, and other oils don't have. But the old Farmalls love it. It keeps them quieter than when using other modern oils. I'm sure synthetic wouldn't be an improvement.
As RustyFarmall said: stick with the 15w40.

dhermesc · Dec 4, 2009

5W-30 will be fine. The oil is as heavy as straight 30W when you get it up to operating temperature - are you afraid to put straight 30W in it in the summer? The 5W means the thickness of the oil at 30 degrees (winter viscocity) is same as it would be if it were 5 weight oil at 30 degrees - still much thicker than 30 weight at operating temp.

When you H was first designed most motor oils did not have zinc added, in fact they were pretty basic with few additives of any kind. In the late 1940s companies began to zinc dialkyldithiophosphate.

Today the zinc issue doesn't apply to engines like the H as they don't have near the piston ring-to-cylinder pressure that high performance engines do (the main reason for the fear of modern oils). After an engine is broke in the the need for zinc is greatly reduced. I bet your H engine is broke in.

In the 1970s and early 1980s there used to be 1,400-1,500 zinc ppm in motor oils (levels were lower before and after that) and current levels are in the 600 to 800 ppm range.

http://www.hotrod.com/pitstop/hrdp_0702_pitstop_zinc_oil_additive/index.html

CLIFF S · Dec 4, 2009

If you want to stick to the Diesel oil Like
15/40 Shell Rotella there is an Option for Winter Use Shell Makes an 10/30 Rotella that will Give you the same kind of Oil thats thinner and Start Better in the Winter!

CNKS · Dec 4, 2009

NO! 5W-30, and in the case of Ford, 5W-20 has only been recommended for automobiles in recent years. Old tractor engines, rebuilt or not have very loose tolerances compared to modern cars.

Anonymous-0 · Dec 4, 2009

Looking at oils other day and now rotella has synthetic 5-40. Sounds like best of both worlds to me.

scot in pa · Dec 9, 2009

I'm not going to say it would start better with the lighter oil, but the lower cold viscosity helps the pump get the oil into the motor faster.

5-30 synthetic in an H ?

riverbend

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rustyfarmall

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Andrew Z

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Mike CA

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dhermesc

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CLIFF S

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CNKS

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Anonymous-0

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scot in pa

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