I recently purchased a 1978 mini. The '78 mini is more or less the same as the first '59 mini, with some subtle body changes. The engine design is a flat tappet style that is unchanged from the '59. The engine and the manual transmission share the same sump / lubricant. The car was imported from England and has no catalysts. The owner's manual suggests 20w-50 motor oil for the combined engine / trans. I have been running Valvoline VR1 20w-50 in the car, but when the oil is cold, the trans needs to be shifted very slowly to prevent the gears from grinding. I suspect my synchros are wearing, but once the oil warms up, the trans shifts perfectly smooth. The cold oil shifting issue has me considering switching lubricants. Considering the odd useage of combined engine / manual trans, do you guys have any oil suggestions?
Oil suggestion for a classic mini?
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How will you use the car?
Short trips? Freeway speeds? Summer use only?
You might also consider fitting an oil pressure and oil temp gauge.
before you make a decision to possibly switch to a lighter oil like a 15w40.
Many Mini's in the U.K. used an Oil cooler (if driven hard)
EVEN when using 20w-50.
Short trips? Freeway speeds? Summer use only?
You might also consider fitting an oil pressure and oil temp gauge.
before you make a decision to possibly switch to a lighter oil like a 15w40.
Many Mini's in the U.K. used an Oil cooler (if driven hard)
EVEN when using 20w-50.
I think if you switch to the VR1 10-40,it would work better for you. I think you need to treat this thing like a liquid cooled bike,and any specific MC oil for shared sump should work just fine. The best oil I ever used for my Honda cycles was genuine Honda oil. It always shifted better with that oil than anything else.
Originally Posted By: expat
How will you use the car?
Short trips? Freeway speeds? Summer use only?
You might also consider fitting an oil pressure and oil temp gauge..
Does the car have an OP guage?
You can certainly take advantage of modern synthetic oils. The low VI 20w50 is certainly too thick on start-up so you could benefit from a lighter higher VI oil as long as you can still maintain adequate OP.
If you can maintain normal hot OP with Mobil 1 0W-40 (HTHSV 3.8cP, 185 VI) that for sure will improve your cold shifting quality. It's cheap and easily available.
A heavier option is Mobil Delvac 1 ESP 0W-40 (HTHSV 4.0cP, VI 186).
If you don't mind the cost Red Line 0W-40 (HTHSV 4.0cP, VI 197) is heavier than Mobil 1 and it can be thickened up further with the addition of some Red Line 5W-50 (HTHSV 5.9cP, 185 VI).
Another option would be Sustina 0w50 (est HTHSV 4.2cP, VI 206).
How will you use the car?
Short trips? Freeway speeds? Summer use only?
You might also consider fitting an oil pressure and oil temp gauge..
Does the car have an OP guage?
You can certainly take advantage of modern synthetic oils. The low VI 20w50 is certainly too thick on start-up so you could benefit from a lighter higher VI oil as long as you can still maintain adequate OP.
If you can maintain normal hot OP with Mobil 1 0W-40 (HTHSV 3.8cP, 185 VI) that for sure will improve your cold shifting quality. It's cheap and easily available.
A heavier option is Mobil Delvac 1 ESP 0W-40 (HTHSV 4.0cP, VI 186).
If you don't mind the cost Red Line 0W-40 (HTHSV 4.0cP, VI 197) is heavier than Mobil 1 and it can be thickened up further with the addition of some Red Line 5W-50 (HTHSV 5.9cP, 185 VI).
Another option would be Sustina 0w50 (est HTHSV 4.2cP, VI 206).
Wondering that with the synchros you don't want something "too" slippery, remembering that the particular engine/trans combo was engineered for what was around at the time, and as per Doug's advice, vice versa, the oils were made for that.
If it were mine, I'd drop back to Castrol GTX 20W-50, or Valvoline XLD 20W-50, see how it goes fora few weeks, and then decide a strategy.
Unfortunately, I don't think you have that option.
If it were mine, I'd drop back to Castrol GTX 20W-50, or Valvoline XLD 20W-50, see how it goes fora few weeks, and then decide a strategy.
Unfortunately, I don't think you have that option.
Thanks for all of the responses. To answer some of the questions:
The car sees mixed useage. It is a fun car, not a daily driver. The longest trip we have taken to date was 100 miles one way on the highway. 70 MPH in this thing is 4400 RPM, so I don't know if my ears could go much longer on the highway. We have also autocrossed the car, and driven it normally. We have driven it in weather as cold as 30F and as warm as 98F. It generally sees 10 - 20 mile trips, but occasionally we take it on 50 - 100 mile trips. That said we only have put 2k miles on it since we purchased it last fall. Oil change intervals and oil cost are kinda irrelavant to me due to the low annual mileage.
The first oil change I did, I used Rotella 15w40 conventional oil. It shifted OK, but not great when particularly cold. A guy at a mini meet told me to try the VR1 20w-50 and it degraded cold shifts, and I do not know if it did anything better...
The car is fitted with an oil cooler.
The car has an OP gauge. It normally reads about 20PSI at idle, and 50 - 60 driving around normally. (Did that with both the VR1 20w-50 and the Rotella 15w40)
The car sees mixed useage. It is a fun car, not a daily driver. The longest trip we have taken to date was 100 miles one way on the highway. 70 MPH in this thing is 4400 RPM, so I don't know if my ears could go much longer on the highway. We have also autocrossed the car, and driven it normally. We have driven it in weather as cold as 30F and as warm as 98F. It generally sees 10 - 20 mile trips, but occasionally we take it on 50 - 100 mile trips. That said we only have put 2k miles on it since we purchased it last fall. Oil change intervals and oil cost are kinda irrelavant to me due to the low annual mileage.
The first oil change I did, I used Rotella 15w40 conventional oil. It shifted OK, but not great when particularly cold. A guy at a mini meet told me to try the VR1 20w-50 and it degraded cold shifts, and I do not know if it did anything better...
The car is fitted with an oil cooler.
The car has an OP gauge. It normally reads about 20PSI at idle, and 50 - 60 driving around normally. (Did that with both the VR1 20w-50 and the Rotella 15w40)
If you see that kind of oil pressure driving around normally, you could certainly try something thinner.
I'd try Mobil 1 0W-40 and see how it does.
An even cheaper option would be Rotella T6, which seems to do fine in shared sump bikes.
After all, oils have improved since 20W-50 was developed for the Mini.
Oh, they are really neat little cars.
They make the current BMW Mini look huge.
I'd try Mobil 1 0W-40 and see how it does.
An even cheaper option would be Rotella T6, which seems to do fine in shared sump bikes.
After all, oils have improved since 20W-50 was developed for the Mini.
Oh, they are really neat little cars.
They make the current BMW Mini look huge.
Thank's for the info'
I believe the by-pass point is set quite low on BMC cars including the Mini; 60 psi max' does come to mind.
There was another thread on the subject and the poster at the time was experimenting with motorcycle 10W-40 4T oils.
As a point of interest, as a kid back in the early 70's we had a Mini in the family amongst other BMC cars, and we never used anything heavier than 5W/10-30/40 oils in them year round.
Check your OP by-pass point (you maximum OP at elevated rev's cold). I suspect you're running in by-pass with the VR1 20W-50 which is not a good thing to do and a sure sign that the oil is way heavier than necessary.
And forget the low VI 15w40 which is super heavy cold compared to modern oils like Shell Rotella T6 5W-40 that fdgc27 mentioned (HTHSV 4.0cP, 169 VI).
I suspect you shouldn't need to run anything heavier than the T6 but Mobil 1 0W-40 would be ideal if can still maintain 58-59 psi hot at 4,500 rpm and the car should be a lot more driveable without worrying about beating the syncro's when cold.
I believe the by-pass point is set quite low on BMC cars including the Mini; 60 psi max' does come to mind.
There was another thread on the subject and the poster at the time was experimenting with motorcycle 10W-40 4T oils.
As a point of interest, as a kid back in the early 70's we had a Mini in the family amongst other BMC cars, and we never used anything heavier than 5W/10-30/40 oils in them year round.
Check your OP by-pass point (you maximum OP at elevated rev's cold). I suspect you're running in by-pass with the VR1 20W-50 which is not a good thing to do and a sure sign that the oil is way heavier than necessary.
And forget the low VI 15w40 which is super heavy cold compared to modern oils like Shell Rotella T6 5W-40 that fdgc27 mentioned (HTHSV 4.0cP, 169 VI).
I suspect you shouldn't need to run anything heavier than the T6 but Mobil 1 0W-40 would be ideal if can still maintain 58-59 psi hot at 4,500 rpm and the car should be a lot more driveable without worrying about beating the syncro's when cold.
A BMC on cold thick oil normally baulked on gearshifts, getting better as it warmed up, to be crunching the syncro (baulk) rings must be really shot.
My mother bought a Mini brand new in 1968, drove it every day and looked after it well. Gearchanges baulked badly on every shift, so you learned never to force it and just make good shifts (we were a trucking family, double de clutch was just what we all did in all vehicles). She sold it after 7 years to a neighbour, and my mate thrashed it unmercifully, I used to hate being in the car with him seeing my mother's car treated like that. After only a few months the gearchange was floppy and sometimes crunchy.
My mother bought a Mini brand new in 1968, drove it every day and looked after it well. Gearchanges baulked badly on every shift, so you learned never to force it and just make good shifts (we were a trucking family, double de clutch was just what we all did in all vehicles). She sold it after 7 years to a neighbour, and my mate thrashed it unmercifully, I used to hate being in the car with him seeing my mother's car treated like that. After only a few months the gearchange was floppy and sometimes crunchy.
Thanks for all of the suggestions. My next oil change will be T6 5w-40... We will see what happens.
Originally Posted By: 2Slow
Thanks for all of the suggestions. My next oil change will be T6 5w-40... We will see what happens.
I think you will be very happy with the T6. I've done quite a bit of reading on the use of the product outside it's advertised use as diesel engine oil. People have been very successful in using it in cars like yours (shared sump for engine and transmission ), motorcycles and atv's.
Thanks for all of the suggestions. My next oil change will be T6 5w-40... We will see what happens.
I think you will be very happy with the T6. I've done quite a bit of reading on the use of the product outside it's advertised use as diesel engine oil. People have been very successful in using it in cars like yours (shared sump for engine and transmission ), motorcycles and atv's.
Originally Posted By: 2Slow
My next oil change will be T6 5w-40... We will see what happens.
You could do that, or try Mobil 1 0W-40 instead but don't fill the sump past the low level initially. Take the car for a run to do a hot oil pressure test. If you getting 58-59 psi at high rev's that's perfect and the T6 would have been too heavy, so you can then top up with some more 0W-40. If you're still getting 60 psi then the Mobil 1 0W-40 is still too heavy and you could top up to the full level with some Mobil 1 0W/5w30 or even some Mobil 1 0W-20 if you're seeing 60 psi at even moderately high rev's.
If you're not getting 58 psi, then you could top up with some Mobil 1 5W-50 (if you can find it) or some Mobil 1 15W-50 which is readily available. I don't recall the Mini's sump capacity but assuming for the sake of argument that it's 4 quarts, one qt of 15W-50 will give you the same hot operational viscosity as T6 but still be lighter on start-up. (BTW all Mobil 1 oils are mixable without issue).
The thing is, Mobil 1 0W-40 is only 5% lighter than T6 at operating temp's, but due to it's higher VI almost 20% lighter at room temperature and 25% lighter at 0C. This will optimize both your cold shift quality and the engine oil viscosity for your Mini.
My next oil change will be T6 5w-40... We will see what happens.
You could do that, or try Mobil 1 0W-40 instead but don't fill the sump past the low level initially. Take the car for a run to do a hot oil pressure test. If you getting 58-59 psi at high rev's that's perfect and the T6 would have been too heavy, so you can then top up with some more 0W-40. If you're still getting 60 psi then the Mobil 1 0W-40 is still too heavy and you could top up to the full level with some Mobil 1 0W/5w30 or even some Mobil 1 0W-20 if you're seeing 60 psi at even moderately high rev's.
If you're not getting 58 psi, then you could top up with some Mobil 1 5W-50 (if you can find it) or some Mobil 1 15W-50 which is readily available. I don't recall the Mini's sump capacity but assuming for the sake of argument that it's 4 quarts, one qt of 15W-50 will give you the same hot operational viscosity as T6 but still be lighter on start-up. (BTW all Mobil 1 oils are mixable without issue).
The thing is, Mobil 1 0W-40 is only 5% lighter than T6 at operating temp's, but due to it's higher VI almost 20% lighter at room temperature and 25% lighter at 0C. This will optimize both your cold shift quality and the engine oil viscosity for your Mini.
With that shared sump for the transmission and engine, you need an oil that is robust. 20-50 or 15-40 are my first choices.
I doubt you are going to drive the car in winter, but if you do, the 5-40 would be great.
I doubt you are going to drive the car in winter, but if you do, the 5-40 would be great.
What would happen if Castrol 5w50 synthetic was used? You do complain about difficult cold weather shifting.
I would bias the oil for when it is warm, not cold.
There is a reason no cars use combined transmission and engine sumps, except this one.
There is a reason no cars use combined transmission and engine sumps, except this one.
I changed the oil to Rotella T6 5w-40 Saturday and have the following observations:
1) The cold temp shifts are much better. No grinding, just a little stiff until the oil warms, than it shifts like butter.
2) My poor British seals are leaking a lot. I used to have a leak that would leave a drip when parked. Needed to add about a quart of oil every 1000 miles. I have only put 250 miles on this oil change and I am already down 1/2 quart. I am going to replace the seals at the trans to CV joint interface as that is where the biggest leak was, but the T6 Rotella leaks a lot more than the VR1 20w-50.
3) When hot, the oil pressure at idle is a down around 18 PSI. It used to be about 25 PSI. At 3000 RPM the oil pressure is the same roughly 60 PSI as it was with the VR1, but below that it is generally a little lower 45 - 55 PSI. The oil bypass on the car is set to 60 PSI.
Any thoughts?
-Joe
1) The cold temp shifts are much better. No grinding, just a little stiff until the oil warms, than it shifts like butter.
2) My poor British seals are leaking a lot. I used to have a leak that would leave a drip when parked. Needed to add about a quart of oil every 1000 miles. I have only put 250 miles on this oil change and I am already down 1/2 quart. I am going to replace the seals at the trans to CV joint interface as that is where the biggest leak was, but the T6 Rotella leaks a lot more than the VR1 20w-50.
3) When hot, the oil pressure at idle is a down around 18 PSI. It used to be about 25 PSI. At 3000 RPM the oil pressure is the same roughly 60 PSI as it was with the VR1, but below that it is generally a little lower 45 - 55 PSI. The oil bypass on the car is set to 60 PSI.
Any thoughts?
-Joe
Originally Posted By: 2Slow
I changed the oil to Rotella T6 5w-40 Saturday and have the following observations:
1) The cold temp shifts are much better. No grinding, just a little stiff until the oil warms, than it shifts like butter.
2) My poor British seals are leaking a lot. I used to have a leak that would leave a drip when parked. Needed to add about a quart of oil every 1000 miles. I have only put 250 miles on this oil change and I am already down 1/2 quart. I am going to replace the seals at the trans to CV joint interface as that is where the biggest leak was, but the T6 Rotella leaks a lot more than the VR1 20w-50.
3) When hot, the oil pressure at idle is a down around 18 PSI. It used to be about 25 PSI. At 3000 RPM the oil pressure is the same roughly 60 PSI as it was with the VR1, but below that it is generally a little lower 45 - 55 PSI. The oil bypass on the car is set to 60 PSI.
Any thoughts?
-Joe
you're still hitting the bypass valve limit then.
drop the oil to a 30wt and see what happens.
Idling pressure is not so important as there is very little load on the engine.
I only get 10 psi at hot idle on my old alfa!! But 45-50 psi at 3000 rpm (but my bypass opens at 88 psi) so within a good limit.
Good to have the option of going to a thinner oil rather than a thicker one as in my case.
I changed the oil to Rotella T6 5w-40 Saturday and have the following observations:
1) The cold temp shifts are much better. No grinding, just a little stiff until the oil warms, than it shifts like butter.
2) My poor British seals are leaking a lot. I used to have a leak that would leave a drip when parked. Needed to add about a quart of oil every 1000 miles. I have only put 250 miles on this oil change and I am already down 1/2 quart. I am going to replace the seals at the trans to CV joint interface as that is where the biggest leak was, but the T6 Rotella leaks a lot more than the VR1 20w-50.
3) When hot, the oil pressure at idle is a down around 18 PSI. It used to be about 25 PSI. At 3000 RPM the oil pressure is the same roughly 60 PSI as it was with the VR1, but below that it is generally a little lower 45 - 55 PSI. The oil bypass on the car is set to 60 PSI.
Any thoughts?
-Joe
you're still hitting the bypass valve limit then.
drop the oil to a 30wt and see what happens.
Idling pressure is not so important as there is very little load on the engine.
I only get 10 psi at hot idle on my old alfa!! But 45-50 psi at 3000 rpm (but my bypass opens at 88 psi) so within a good limit.
Good to have the option of going to a thinner oil rather than a thicker one as in my case.
I can purchase a Cooper S spring for $4, that would bump the bypass pressure to 70 PSI, is that something you guys would advise?
Originally Posted By: 2Slow
I can purchase a Cooper S spring for $4, that would bump the bypass pressure to 70 PSI, is that something you guys would advise?
noo. the bypass pressure was designed for your engine in mind.
If you exceed this pressure, seals can pop, filters explode, gaskets leak etc.
I would never alter the bypass spring rate.
Just find a thinner oil to suit the engine.
I can purchase a Cooper S spring for $4, that would bump the bypass pressure to 70 PSI, is that something you guys would advise?
noo. the bypass pressure was designed for your engine in mind.
If you exceed this pressure, seals can pop, filters explode, gaskets leak etc.
I would never alter the bypass spring rate.
Just find a thinner oil to suit the engine.
Even if the engine would prefer lower viscocity, I am a little leary about lowering the viscoscity much as it is the same lube for the trans sump. Many manual trans / axle configurations run a fairly high viscocity lube compared to 40w engine oil.
The seals are the same between my engine and the Cooper S, so I doubt there would be any issue going to the 70 PSI spring, but I doubt I should mess with a system that works.
-Joe
The seals are the same between my engine and the Cooper S, so I doubt there would be any issue going to the 70 PSI spring, but I doubt I should mess with a system that works.
-Joe
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