# Changed to M1 5W40 TDT...interesting fanny dyno results...



## meb58 (Jun 22, 2009)

This is not a VW, but I recently changed from garden variety M1 5W30 to M1 5W40 TDT based upon results here, tests, and, UOAs. The car now has 164,000 miles on it.
If I believe the guages, and i have plenty of experience with them, cold start-up oil pressure is a tad higher, oil psi on a completely warmed up engine at 80 mph constant is a few tads lower and mpg went up by .4 mpg - according to the on board computer. Driving conditions and style are the same. The improvement in mpg was after one day or about 140 miles of highway/city driving.
I drive about 3,000 miles a month, so no Redline in this car. I have never performed a UOA on this car, but I think will follow up here in a month with that report...I should have performed one with the other oil for a comparison...


_Modified by meb58 at 5:41 AM 7-23-2009_


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## saaber2 (Jul 15, 2008)

*Re: Changed to M1 5W40 TDT...interesting fanny dyno results... (meb58)*


_Quote, originally posted by *meb58* »_cold start-up oil pressure is a tad higher, oil psi on a completely warmed up engine at 80 mph constant is a few tads lower and mpg went up by .4 mpg - according to the on board computer. 

This all is consistent with what you would expect of an oil with a higher HTHS and stronger additive pack than the pretty poor m1 5w30. M1 TDT is a much better oil than the M1 5w30. If it is a non-turbo and non fuel-diluting application, you may be able to stretch OCI for a long ways (with UOAs) with this oil, especially if you are mostly hwy miles. I don't know your application, but 7k might be a conservative point to get a UOA on this oil assuming it is normally aspirated car and not severe service. Depending on UOA results, you could possibly double that for the above assumed conditions.



_Modified by saaber2 at 9:32 AM 7-23-2009_


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## meb58 (Jun 22, 2009)

saaber2,
I was hoping you would reply...This is the Mini - supercharged. I keep my speed/rpms on the highway and side roads well within sane levels.
Thank you for pointing this oil out. I'll let the oil change interval go for 5,000 miles then report back...I already know I should see elevated Fe levels since this car has a timing chain. What else might you expect?
Also, regarding my wife's 07 Passat turbo, what fluid do we use in the transaxle? I'm assuming Redline is perfect here. Iuse their gear oiol in the Mini.



_Modified by meb58 at 10:31 AM 7-23-2009_


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## saaber2 (Jul 15, 2008)

*Re: (meb58)*


_Quote, originally posted by *meb58* »_I'll let the oil change interval go for 5,000 miles then report back...I already know I should see elevated Fe levels since this car has a timing chain. What else might you expect 

My guess is you will see reduced iron levels compared to the 5w30. You may not see this until the 3rd oil change however due to the effect of residual old oil but mostly the chemistry of the new oil working on the oxidation layer. But there is a good chance you will see it immediately. I would also guess that your oil at 5k will appear to be able to go 15k based on viscosity loss, TBN, etc. but I haven't seen many mini UOAs. It's smart to do a UOA on the shorter side, like 5-7k to see where you are at. I'll bet the UOA of the second or third oil change will indicate an OCI of 10k-15k but who knows. That is why the UOA is so valuable. 
What is the nature of the supercharger? Does it share the engine's oil? If so, that could change the dynamic considerably and would further increase the value of a 5k UOA and you may well see other metals one wouldn't normally expect in a NA engine at the 5k mark with that oil.


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## meb58 (Jun 22, 2009)

The SC is a sealed unit, unfortunately. some have leaked leaving the driver/owner without forced induction. The entire SC must be replaced at that point. Every car has its idiocyncracies.
Okay, I'll get back here is 5,000 miles...end of August.
Final question...how do I go about performing an UOA? Rather, who do you like?


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## saaber2 (Jul 15, 2008)

*Re: (meb58)*


_Quote, originally posted by *meb58* »_Final question...how do I go about performing an UOA? Rather, who do you like?

Depends on how much you want to spend. Dyson analysis is probably the best but it is like $100 or more I think. I don't support this company and never will because it forces you to sign a legal document saying that you won't share the information with anyone. It even talks about how they can take legal action against you as I remember. I wouldn't sign up for that even if it was free. What is the good of learning something about your car if you can't share it with anyone. No thanks, not for me.
Blackstone is probably the most popular and a test is around $25. $10 more for TBN and $10 more for TAN. I use Blackstone probably just because that is who I started with. I will say there results are o.k. and their interpretation, well, let's just say it's not the most useful sometimes. But they have consistently given me excellent customer service and will re-run things right away if you think there is a problem.
Wear check I think will do everything including TBN and TAN for around $25. I have heard some negative reports about them on BITOG but have never used them myself. Price is amazing.
Whatever lab you choose, stick with that lab as results across labs really aren't comparable. If you really want to know how far you can go with your oil, spring for both a TBN and TAN on one of the samples (no need to do it every time unless you want to). I bet at 5k your TBN will be quite high (good) and your TAN quite low (good). As a general rule, when the TAN (total acid number) meets or exceeds the TBN (Total base number), that is when you want to change your oil. 
This is not really true for all oils though. Some ester-based oils start with a higher TAN and some esters actually have a lower TAN as the oil is used (Renewable lubricants for example). But for most oils that general rule works.
I bought the little blackstone pump and it works really slick because you can take a sample from the dipstick tube and not have to change the oil. So if you check it at 5k lets say and find you can go much longer, you just stay with the same oil. No oil goes into the pump so you just put a new piece of plastic tubing on it each time. It's worth the cost to me. http://www.blackstone-labs.com/pump.html
One final thing to really pay attention to. I heard that if you mail the little white bottle in a bubble envelope mailer with regular stamps and don't write liquid or anything outside, it takes 1-2 days from the west coast to reach BS labs in indiana for example. I heard that if you use the little black mailing round bottle it takes around 25 days to go the same distance and i've heard some horror stories of months. Just what I heard...










_Modified by saaber2 at 6:01 PM 7-24-2009_


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## meb58 (Jun 22, 2009)

Thank you!


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