Is 20-50 oil OK ??

[Mangizmo]

I have 40Ltrs of 20-50 oil freebie, can I use it in my Ural 750 2012, spec says 15-40 but will this be OK (engine /gearbox ?)

[Daytripper]

Here in the states they spec 20w-50.

[Mangizmo]

Sorry my mistake, the 40ltrs I have is 15-40, can I use this ??.....its free!!

[BinDerSmokDat]

With multi-viscosity oils the lower number only comes into play in very cold weather, somewhere down around 0-32F.
The larger number is the "hot" number, when oil is warmed up.

15-40 would be fine for winter here, but I'm not certain UK winters are cold enough, it would probably too low a viscosity.

[GregAus]

15W40 is fine to use all year round. Original Ural specs for the 650 was SAE 20W30. The 750 has not changed enough to disqualify that. If it's diesel oil it's probably better than a 20W50 car oil.

[Bilgekeeldave]

Moved to "Oil Threads" in the Order of the Greasy Wrench forum.

Forum Section Tech Support is for website tech support, you know, computer stuff, not motorcycle stuff.

[rivers]

DISCLAIMER: personal opinion only:
In the mild climate of the UK, if it's a quality brand I would probably use it for normal use. If I were hammering the hills in SE USA prolly not. At least not in summer.

[Fredrikrosen]

15W40 is fine to use all year round. Original Ural specs for the 650 was SAE 20W30. The 750 has not changed enough to disqualify that. If it's diesel oil it's probably better than a 20W50 car oil.

Ural have never speced anything else than 20W50 for their engines, maybe the US importer claim so but that is pure bs.

[GregAus]

15W40 is fine to use all year round. Original Ural specs for the 650 was SAE 20W30. The 750 has not changed enough to disqualify that. If it's diesel oil it's probably better than a 20W50 car oil.

Ural have never speced anything else than 20W50 for their engines, maybe the US importer claim so but that is pure bs.

You need to find some 650 manuals and read them. SAE 20W30 is specified. It was CSMI that first specified 20W50 and IMWA had to continue that to avoid recertification. The original R71 and M-72 specs were SAE 20 (cSt 8) in Winter and SAE30 (cSt 10) in Summer.

[Fredrikrosen]

15W40 is fine to use all year round. Original Ural specs for the 650 was SAE 20W30. The 750 has not changed enough to disqualify that. If it's diesel oil it's probably better than a 20W50 car oil.

Ural have never speced anything else than 20W50 for their engines, maybe the US importer claim so but that is pure bs.

You need to find some 650 manuals and read them. SAE 20W30 is specified. It was CSMI that first specified 20W50 and IMWA had to continue that to avoid recertification. The original R71 and M-72 specs were SAE 20 (cSt in Winter and SAE30 (cSt 10) in Summer.

I have original ussr manuals and the earliest ones dont even mention SAE grade oil at all and the later ones clearly says 20W50. The US manuals are far from correct.

[RC20]

Per GregAUS, 15-40 would be fine in the engine.

Preferably a diesel 15-40. Not have to, but it gives you more latitude for higher temps than a regular 15-40. Very very good quality oil.

I don't know what difference in the trany there are between the machines. I ran 15-40 in the Japanese bikes and the BMW engine. I forget what ran in the R80 tranny. Have to look that up. I would consider VW 505.01 oil for the Trany. Its both synthetic and has an EP additive. Its not shearing polymers, its to avoid surface to surface contact. That theory, reality may mean it really does not matter as long as you have good recommended oil in there.

I did move to synthetic in all boxes on the R80 as I was running some pretty cool temps (20 at worst). I think the Ural move to synthetic is not a bad idea as the machines certainly can do some winter running.

[GregAus]

I have original ussr manuals and the earliest ones dont even mention SAE grade oil at all and the later ones clearly says 20W50. The US manuals are far from correct.

The Soviet manuals don't mention SAE numbers because the GOSTANDART measured oil grades in centistokes (cSt) thus the requirement for the engine and gearbox of М-8В in Winter and М-10Г in Summer. The 1992 the German/Spanish Service book specifies М-8В with multigrade equivalents of М6з/12Г and М5з/10Г (з meaning зима or Winter). It lists SAE equivalents as SAE 30, SAE 20W20 and SAE 20W30.

If you look at the SAE definitions for Grade Designation you find the following kinematic viscosities measured in cSt.
20 5.6 - 9.3
30 9.3 - 12.5
40 12.5 - 16.3
50 16.3 - 21.9
60 21.9 - 26.1

From the above you can see that М-8В is equivalent to SAE 20, М-10Г is equivalent to SAE 30, М6з/12Г is equivalent to SAE 20W30 and М5з/10Г would be approximately equivalent to a modern SAE 15W30.

[GregAus]

Ural have never speced anything else than 20W50 for their engines, maybe the US importer claim so but that is pure bs.

Ural manual from the late 1990s specifying SAE 15W40

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