Hi, I’ve just had a read through the wiki but not been able to find a breakdown of what products are recommended for servicing an M20B25 engine.
Appreciate it if some of the more experienced owners can share what their go to products are for the following:
- Oil
- Spark Plugs
- Coolant
- PAS Fluid
- Brake Fluid
Thanks in advance.
M20B25 Service Items
Moderator: martauto
- paultv
- E30 Zone Squatter

- Posts: 1541
- Joined: Mon Apr 21, 2014 11:00 pm
- Location: Auf dem Schnee: Germany
Always check the condition of the distributor cap and rotor....if its worn, pitted which it will be...replace it, it's night and day when you fit a new one ...of course you can clean the posts and file them clean as with the rotor but this increases depressions making the spark jump further causing increased pitting.
Paul
Paul
4th May 1990 325i Convertible.
BMW E30 Cabriolet Best Mod Ever:
https://bmwe30cabriolet-wdm.blogspot.com/
BMW E30 Cabriolet Best Mod Ever:
https://bmwe30cabriolet-wdm.blogspot.com/
- Tzantushka
- E30 Zone Regular

- Posts: 464
- Joined: Sat Nov 24, 2018 4:18 am
- Location: Melbourne, Australia
Have a look in the Wiki as most recommendations are in there
e.g. spark plugs -> https://www.e30zone.net/e30wiki/index.php/Ignition
With Oil, be prepared for lots of opinions for lots of climates for lots of driving conditions - oh yes... and lots of change intervals.
Best to stick with what's in the manual for oil grade.
But look for an oil with a high anti-wear additive (e.g. Zinc commonly a ZDDP additive)
I'm in Australia so can only give you suggestions for our country.
For coolant, BMW (blue) coolant is proven.
e.g. spark plugs -> https://www.e30zone.net/e30wiki/index.php/Ignition
With Oil, be prepared for lots of opinions for lots of climates for lots of driving conditions - oh yes... and lots of change intervals.
Best to stick with what's in the manual for oil grade.
But look for an oil with a high anti-wear additive (e.g. Zinc commonly a ZDDP additive)
I'm in Australia so can only give you suggestions for our country.
For coolant, BMW (blue) coolant is proven.
For coolant I use Comma xStream G48 and a 5w40 engine oil. I've used Millers CFS and Fuchs Titan Race Pro S & live in the south east and took the car out in the snow to drift earlier this year with no problems. I have replaced the oil twice in the year and a bit that I've owned the car purely as a 'might as well while i'm here' with other servicing.
For plugs I use NGK ZGR5A (5839)
Comma Power Steering Fluid and Conditioner is what I used earlier this year to replace mine.
With brake fluid it depends what your requirements/preference is. A good DOT 4 from any name brand will be fine but you can get super DOT 4 if you want a higher boiling point. MOTUL RBF is high quality or ATE typ 200.
For the distributor cap and rotor arm DO NOT buy the BREMI cap from autodoc, it's black cover is a terrible fit (doesn't clear the metal coolant pipe properly) or the Bosch ignition leads unless you're willing to take the plastic cover off because the leads aren't numbered.
I have an M20B20 but those service parts should be the same.
PS Don't forget to check your valve clearances!
Enjoy and take your time with things and getting to know your E30
For plugs I use NGK ZGR5A (5839)
Comma Power Steering Fluid and Conditioner is what I used earlier this year to replace mine.
With brake fluid it depends what your requirements/preference is. A good DOT 4 from any name brand will be fine but you can get super DOT 4 if you want a higher boiling point. MOTUL RBF is high quality or ATE typ 200.
For the distributor cap and rotor arm DO NOT buy the BREMI cap from autodoc, it's black cover is a terrible fit (doesn't clear the metal coolant pipe properly) or the Bosch ignition leads unless you're willing to take the plastic cover off because the leads aren't numbered.
I have an M20B20 but those service parts should be the same.
PS Don't forget to check your valve clearances!
Enjoy and take your time with things and getting to know your E30
1990 4-door 320i SE
Thanks very much!Lemon98 wrote: ↑Sun Jun 06, 2021 5:50 pmFor coolant I use Comma xStream G48 and a 5w40 engine oil. I've used Millers CFS and Fuchs Titan Race Pro S & live in the south east and took the car out in the snow to drift earlier this year with no problems. I have replaced the oil twice in the year and a bit that I've owned the car purely as a 'might as well while i'm here' with other servicing.
For plugs I use NGK ZGR5A (5839)
Comma Power Steering Fluid and Conditioner is what I used earlier this year to replace mine.
With brake fluid it depends what your requirements/preference is. A good DOT 4 from any name brand will be fine but you can get super DOT 4 if you want a higher boiling point. MOTUL RBF is high quality or ATE typ 200.
For the distributor cap and rotor arm DO NOT buy the BREMI cap from autodoc, it's black cover is a terrible fit (doesn't clear the metal coolant pipe properly) or the Bosch ignition leads unless you're willing to take the plastic cover off because the leads aren't numbered.
I have an M20B20 but those service parts should be the same.
PS Don't forget to check your valve clearances!
Enjoy and take your time with things and getting to know your E30![]()

