44 replies to this topic

[JDMRoverMini]

I’ve read to use 20w-50 oil, and Miller’s brand is good. I live in Chicago, and we have cold winters and hot summers, not the typical classic mini environment. Should I stick with this, or go to something different , like 10w-50?

[Spider]

It probably would be beneficial to look at the grade of Oil you might choose.

 

Here's the factory's recommendations;-

 

 

[Ethel]

Rover spec'd 15W40 for the UK from about 1980. The gearbox is the main consideration, something with a decent dose of ZDDP & mineral seems to survive the chewing from gear teeth longer than synthetic. Motorcycle oil has also been tried by the big power turbo builders as it's also brewed for gearbox in sump. 

[cal844]

Rover tweaked the oil requirements to be inline with the rest of the range, ultimately resulting in 10w40 being used in early MPIs that needed replacement units early in the warranty period

[richmondclassicsnorthwales]

I have always used 20/50, and never used anything else with classic car engines - Mini - MG - and so on

 

Never had any bother at all, in my early years, I  had all my cars sat on a roadside / curb side in all weathers outside the house

 

In the last few years, I have fitted oil coolers to my cars, the MG Midget runs with one, and I would say it also keeps the coolant cooler too. Come winter, blank off the oil cooler with kitchen foil. (we wont go down different rabbit holes about oil thermostats)

 

I suppose what I am saying is "If it's not broke - don't fix it.  One thing I would say is to do more oil changes than what is stipulated - good oil = good engine and box.

 

Just my findings with the good old BLMC engines

[nicklouse]

I would say a 10-40 should be fine for your weather. 
 

but you don’t say what your temps actually are.

[gazza82]

I would say a 10-40 should be fine for your weather. 
 
but you don’t say what your temps actually are.

https://www.google.c...ih=686&dpr=1.75

[Aria Aradhea]

If your car is an automatic (as many JDM-spec cars are), it is better to use 10/40 with JASO MA2 oil spec

[cal844]

If your car is an automatic (as many JDM-spec cars are), it is better to use 10/40 with JASO MA2 oil spec

I agree but for a manual box use 20/50

[Dusky]

I always wonder if the "10w40 destroying gearboxes " stories exist because of poor quality 10w40 or because of the viscosity. I think it's the former.

[Cooperman]

The problem which can arise is that in very cold climates it can be necessary to push the clutch down to start the car due to the thickness of the oil. 

With a 20w50 this can lead to oil starvation at the crankshaft thrust bearings leading to rapid wearing. I had to rebuild a Cooper 'S' engine after crank thrust failure following a Monte carlo Historic rally when the car was started using jump leads after sitting at minus 10 degs all night. The clutch was pushed down and still it was difficult to start.

I think the solution is a 10w40, (or even a 5w30, assuming you can get this in a mineral with high zddp) for really cold climated. Then change to a normal 20w50 from Spring till Autumn. If running a sump guard and you are concerned about oil temp when it really gets going, just fit an oil cooler with a thermostat. With that oil it should start with the clutch engaged.

[weef]

As you can get some prolonged periods in the" minus" temperatures it may be the case for a thinner grade of oil. It was quite the norm in the UK to use a 20w50 multigrade during the summer and switch to 10w30 for the winter before the advent of "modern" synthetic oils. Castrol XL and Castrolite, respectively, spring to mind.

Miller oils, and others, manufacture a 10w30 multigrade mineral oil that has the required high zinc and phosphate levels the "A" series engine and transverse gearbox likes. It does not appear to be a good idea, for  longevity, to use modern synthetic based oils in these units

[JDMRoverMini]

Thank you all for the advice. I’m going with a 20w50 during the summer, and will go with a 15w40 over winter, though it will barely see any miles once it reaches under 40F, and stored in my garage.

[nicklouse]

Thank you all for the advice. I’m going with a 20w50 during the summer, and will go with a 15w40 over winter, though it will barely see any miles once it reaches under 40F, and stored in my garage.

40F is nothing you could happily run 20w50 or 15w40 all year round.

 

 

but you have not confirmed that it is a Manual version.

[JDMRoverMini]

Thank you all for the advice. I’m going with a 20w50 during the summer, and will go with a 15w40 over winter, though it will barely see any miles once it reaches under 40F, and stored in my garage.

40F is nothing you could happily run 20w50 or 15w40 all year round.


but you have not confirmed that it is a Manual version.

Auto trans

Edited by JDMRoverMini, 15 June 2021 - 05:37 PM.