Amsoil Gear lube test

[diyanich]

For those who is about to get the differentials flushed,a pretty cool link I found on the other forum:

http://www.syntheticoilhq.com/pdf/g2...comparison.pdf

I just got a Castrol Syntec 75W90...it fails the foaming test,but overall not that bad.

[JCL]

Interesting tests, thanks for posting it.

A few comments:

• The tests would mean more if they were more independent. Amsoil decided what to test, and what to publish. I don't doubt that the tests were run according to ASTM standards, but they are not unbiased and they published what they wanted to. Having a notary public sign the report doesn't mean anything to me, but an having an accredited engineer do so might have.
• I don't think that differentials are particularly complicated, or that there are demanding requirements for lubrication, as Amsoil claims. EP lubes have been produced for years. Hypoid gears have been used in differentials since the 1920s.
• There are quite a few references made to most vehicles operating under severe service requirements, but I don't think that is true for the X5.
• The oils tested were limited slip oils, not required by the X5
• The 'boutique' oils from Red Line, Royal Purple, and Lucas, did very poorly. Users of those products may want to review the tests.
• I remember one poster here who had a failed differential. That one was due to the poster changing the fluid, and precipitating the failure. There may have been other diffs replaced, but I think they were early hour, and due to manufacturing defects. My point is that despite most owners following the BMW 'never change it' philosophy, X5 diffs aren't failing. Changing the oil at 100,000 miles doesn't seem like a bad idea at all to me, but it is for insurance, not necessity.

Personally, I would use a name brand oil, like Castrol, Chevron, or Mobil 1, in the correct viscosity.

Thanks again for posting.

[diyanich]

Originally Posted by JCL

Interesting tests, thanks for posting it.

A few comments:

• The tests would mean more if they were more independent. Amsoil decided what to test, and what to publish. I don't doubt that the tests were run according to ASTM standards, but they are not unbiased and they published what they wanted to. Having a notary public sign the report doesn't mean anything to me, but an having an accredited engineer do so might have.
• I don't think that differentials are particularly complicated, or that there are demanding requirements for lubrication, as Amsoil claims. EP lubes have been produced for years. Hypoid gears have been used in differentials since the 1920s.
• There are quite a few references made to most vehicles operating under severe service requirements, but I don't think that is true for the X5.
• The oils tested were limited slip oils, not required by the X5
• The 'boutique' oils from Red Line, Royal Purple, and Lucas, did very poorly. Users of those products may want to review the tests.
• I remember one poster here who had a failed differential. That one was due to the poster changing the fluid, and precipitating the failure. There may have been other diffs replaced, but I think they were early hour, and due to manufacturing defects. My point is that despite most owners following the BMW 'never change it' philosophy, X5 diffs aren't failing. Changing the oil at 100,000 miles doesn't seem like a bad idea at all to me, but it is for insurance, not necessity.

Personally, I would use a name brand oil, like Castrol, Chevron, or Mobil 1, in the correct viscosity.

Thanks again for posting.

Very good points JCL,I agree that it would be biased and yes a public notary isn't any like a pro in the oil business I guess.
On the other hand I have 3 quarts of Castrol Syntec 75w90 for differentials and transfer case fluids flush.215,xxx kms on the clock and I doubt those were ever changed.SA at the dealership says they looked OK,just looked not burnt..but come one..215,xxx sounds like a lot,doesn't it?
Do you think it's a bad idea to refresh the fluids,should I pass?

[JCL]

Originally Posted by diyanich

Very good points JCL,I agree that it would be biased and yes a public notary isn't any like a pro in the oil business I guess.
On the other hand I have 3 quarts of Castrol Syntec 75w90 for differentials and transfer case fluids flush.215,xxx kms on the clock and I doubt those were ever changed.SA at the dealership says they looked OK,just looked not burnt..but come one..215,xxx sounds like a lot,doesn't it?
Do you think it's a bad idea to refresh the fluids,should I pass?

Changing the differentials isn't a bad idea IMO, using that Castrol. Just make sure the job is done correctly, proper fill level, and that there are no leaks, and it will be fine.

There is nothing to burn the fluid in the differentials, they don't have any clutch plates.

That 75w-90 is not the correct fluid for the transfer case, if you were planning on using it there.

Yes, it is a lot of km, but nothing unusual.

[diyanich]

Originally Posted by JCL

Changing the differentials isn't a bad idea IMO, using that Castrol. Just make sure the job is done correctly, proper fill level, and that there are no leaks, and it will be fine.

There is nothing to burn the fluid in the differentials, they don't have any clutch plates.

That 75w-90 is not the correct fluid for the transfer case, if you were planning on using it there.

Yes, it is a lot of km, but nothing unusual.

What should I use in the Transfer Case? mine is pre facelift(non Xdrive)
Dex III Syntetic?

[JCL]

I don't think you will be able to find Dexron III still, but you might. The replacement is Dexron VI.

You may find a synthetic version, but there is no particular reason to use it, as this isn't motor oil. Use a name brand. As long as it is an actual certified Dexron fluid, and doesn't just say "suitable for applications calling for Dexron" on the label, then it is fine.

[TowX]

Interesting if I had a GM or Mopar solid axle rear with limited slip. Test skips some of the well regarded lubes like Motul, Swepco and others.

[imola38]

Not surprisingly the Amsoil won the test overall... I've used Redline for years in my E30 with 220k miles. The trans and diff are as smooth and quiet as ever. I see Redline didn't fall too far behind anyway. Interesting reading but the results are no doubt Biased. This kind of reminds me of those Z-Max infomercials where they would have the different oil on a burner and start an engine block covered in ice etc.


-Ben

[Wayne's World]

Originally Posted by JCL

[*]I remember one poster here who had a failed differential. That one was due to the poster changing the fluid, and precipitating the failure. There may have been other diffs replaced, but I think they were early hour, and due to manufacturing defects.

Strangely I think he's referring to me! I changed both my front and rear diff oils @ 86K miles from the factory Castrol XAF to Castrol Syntec 75w-90. I'm not certain but just changing the fluid didn't lead to the diff failure, instead it was a leaky input seal that lead to its demise. Had I paid greater attention there, I probably wouldn't have had to replace it. My reasoning: the newer, less viscous oil, more easily leaked out of the seals than did the old stuff as I was sauntering down the motorway at a calm 110mph. Albeit, the old stuff looked quite good for 85K miles - still had a golden brown color.

But as JCL has schooled me in the past, color doesn't equate to the effectiveness of the oil.

In the end, I found a junkyard unit with 18K miles on it and my indy filled it up with the Catrol XAF stuff. Did the same for the fronts, just for good measure. I now have 124K miles and no issues since.

[wallyx5]

I used Royal Purple on my diffs....looks like I am a looser,