Should I use conventional oil, or synthetic oil in my tractor.

[Reddogs]

I was bringing my tractor to my mechanic, when he stated something that just startled me. We were talking of the maintenance on the tractor when he said "you should only put in and use synthetic oils in any engine", I was shocked to say the least, as once you put in synthetic oils, as it can lead to damage if you try to switch back on older or high mileage engines. Have the synthetic oils become better, or is it still better to stay with conventional oil in a tractor..?

 

[Username Taken]

I was bringing my tractor to my mechanic, when he stated something that just startled me. We were talking of the maintenance on the tractor when he said "you should only put in and use synthetic oils in any engine", I was shocked to say the least, as once you put in synthetic oils, as it can lead to damage if you try to switch back on older or high mileage engines. Have the synthetic oils become better, or is it still better to stay with conventional oil in a tractor..?

Synthetic is superior to dino oil in every way.

You can switch back and forth as much as you want. If you're low on oil, you can top it off with the same weight/viscosity oil whether it's synthetic or not.

Damage caused by synthetic???? Old Wives tale. But...... I'd be mindful of the age/condition/hours/reputation of the engine. Some of them are just thrown together. Your JD 790 is actually a Yanmar, who make a good engine. Your 3301 should be fine as well

Now. Some of the old Big Block Chevys were so poorly machined that the gummed-up, paraffin-based (Pennsylvania grade) oil was the only thing keeping it from leaking like a sieve at most of its seals. Especially the cam side covers and valve covers.

 

[Reddogs]

Synthetic is superior to dino oil in every way.

You can switch back and forth as much as you want. If you're low on oil, you can top it off with the same weight/viscosity oil whether it's synthetic or not.

Damage caused by synthetic???? Old Wives tale. But...... I'd be mindful of the age/condition/hours/reputation of the engine. Some of them are just thrown together. Your JD 790 is actually a Yanmar, who make a good engine. Your 3301 should be fine as well

Now. Some of the old Big Block Chevys were so poorly machined that the gummed-up, paraffin-based (Pennsylvania grade) oil was the only thing keeping it from leaking like a sieve at most of its seals. Especially the cam side covers and valve covers.

Well, when we did it in older engines, they would seize up, is that still an issue...?

 

[Roadworthy]

You'll find opinions both ways. I use synthetic in my tractor and my cars. If you shop for a crate engine for a car you may find regular oil recommended for the first 500 miles but after that either is okay. What you do is pretty much personal preference and experience.

 

[Username Taken]

Well, when we did it in older engines, they would seize up, is that still an issue...?

If you had an engine seize, it wasn't the fault of the synthetic oil.

In fact, most synthetic oil today isn't even 'real' synthetic..... Long story that will attract the wrong people, but oil is oil and there are different grades, different premiums of oil. For our purposes, 'synthetic' is as far as we need to go for this discussion.

Syn starts to flow much sooner because it is usually a lighter base viscosity, it is much more resistant to heat degradation because it doesn't use Viscosity Index Improvers (VII's) and it lubricates better at high high temps. As well as low temps because it flows not only better, but sooner.

With a multi grade dino oil, if you start out with a base oil of 10w and add VII's to improve it to 30w at temperature, the VII's can break down due to heat, age or contamination, leaving you with a 10w oil trying to lubricate a large, hard-working engine at 200+ degrees. Not good.

Where a 'synthetic' is engineered so that every molecule in it is a 10w-30 or a 5w-40. No VII's to break down under heat, pressure and sheer. Syn can break down, but it takes a lot ore. A whole lot more. None of it's perfect.

Synthetic is far from perfect. And dino is far from being bad oil. Like I said, Syn is just better. Not perfect. Better.

this is boring

 

[deserteagle71]

I was bringing my tractor to my mechanic, when he stated something that just startled me. We were talking of the maintenance on the tractor when he said "you should only put in and use synthetic oils in any engine", I was shocked to say the least, as once you put in synthetic oils, as it can lead to damage if you try to switch back on older or high mileage engines. Have the synthetic oils become better, or is it still better to stay with conventional oil in a tractor..?

Mostly BS.

Sure, synthetic oil may be slightly "better" for your engine once it is broken in. But there are too many old tractors out there like my 60 year old John Deere that have NEVER had synthetic oil in them and are still running fine.

How long do you intend to keep/run your tractor?

 

[ericm979]

The compatibility issue between regular and synthetic was fixed decades ago. You can switch between them.

CUT engines are lightly stressed industrial engines. The average user puts on less than 100 hours a year. They don't really need synthetic oil. It doesn't hurt though, and the cost difference is small. If my tractor had a turbo I'd use synthetic- the turbo can get hot and regular oil can cook in the bearing.

 

[LouNY]

To me one of synthetic oils bigger advantage is in winter starting and initial flow,
the higher temp stability and protection is good to have in the summer also.

I have heard the stories back in the 70's and 80's about synthetic ruining engines,
I never saw one that it did. I did see some that needed a change soon after being switched
because the higher detergent capability was washing crap loose and filling the filters.
Which was why they recommended a cleaner and flush on high houred engines being changed.
And I did see some engines become leakers at the gaskets and a few on seals.

 

[jjeff]

Imo full synthetic seems to leak through gaskets and seals a bit more than conventional on my old tractors also seems to contribute to a bit more blowback, so I use a synthetic blend mostly 10w30 diesel rated, never had any issues on my Kubotas.

 

[bmaverick]

Depends on the season.

Summer = Dino

Winter = Synthetic

Pro/Cons to both and it will be a never ending story till the cows come home. Followed lots of this on the, Bob Is The Oil Guy. Thus, my conclusion with the above. It answers the ability to be more on the Pro side seasonally.

Also do not use synthetic blended oil in bottles or jugs. It's all marketing HYPE. Does any bottle really tell you the percentage ratio of the blend? Thus, there is no way any of them can be consistent either with the blending. There is no API standard for blended oils like that either.