A friend just bought an e30 so helping to baseline his maintenance.
I know many of you use Continental belts, I did too but have since migrated away towards Gates XL. Their application guide calls out longer belts. I used their data sheet info to pick the belts I use on my cars. Here's what I'm using.
M20
Fan/Alt - 7375
A/C - 9319
P/S - 7320
M30
Fan/Alt - 9405
A/C - 9335
P/S - 7335
M42
Fan/Alt - 7400* - 2021 update, belt has stretched and has no more adjustment. Squeals in the morning. Going to replace with next smaller size -7395
A/C - 9345
P/S - 7315
I know many of you use Continental belts, I did too but have since migrated away towards Gates XL. Their application guide calls out longer belts. I used their data sheet info to pick the belts I use on my cars. Here's what I'm using.
M20
Fan/Alt - 7375
A/C - 9319
P/S - 7320
M30
Fan/Alt - 9405
A/C - 9335
P/S - 7335
M42
Fan/Alt - 7400* - 2021 update, belt has stretched and has no more adjustment. Squeals in the morning. Going to replace with next smaller size -7395
A/C - 9345
P/S - 7315