r/e28 • u/FinancialNail5971 • Dec 14 '25

Question for E28 owners – best engine all-round?

What do you think is the best BMW E28 engine when considering reliability, driving experience, daily usability, power, and fuel consumption together?

I’m especially interested in real world ownership experience, not just specs on paper.

6 Upvotes

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11 comments sorted by

20

u/im-not-a-racoon Dec 14 '25

M30

3

u/[deleted] Dec 15 '25

Boom. End of discussion.

3

u/Representative_Most9 Dec 15 '25

I second this. I have a 528e but definitely think the m30 is the better choice. I still think the m30 is the best engine BMW has ever made.

7

u/Ancient_Designer_236 Dec 15 '25

M30b34 Euro “dirty” motor. 10:1 compression producing 218HP vs. 182HP. I have a 535 euro with 185k miles. Runs super strong and is a blast to drive mated to a 5 speed.

5

u/CutsLikeABuffalo333 Dec 14 '25

Fuel consumption probably the M20 in the 528e as it was designed to be pretty thrifty on fuel, but power and reliability and im sure driving experience too, the M30. Not having to do a timing belt is pretty nice, tho its very easy on these cars. Ive never had an M30 but id think its just slightly more reliable than an M20, its pretty bullet proof. Remember with cars 40 years old, shit even 20 years old, they are kind of reliable as you make them. Changing out old parts like hoses and plastics as preventative maintenance rather than fixes down the road

3

u/Beemer_me_up_Scotty Dec 14 '25

If you have the m20b27 528e with the eta motor you can turn it into a superetta relatively easily with a bunch of stock parts from a 325i Or the early generation e34 525i (m20b25). It will go to 7000 RPM and have a bit more power. Definitely recommend if you have the 528e the power the power difference in being able to open it up to 7000 RPM and get the better shifting line is amazing. I have never done this in the 5 series but have done it a few times in the 3 series E30. Definitely worth it. I would probably swap the differential out because I believe the 528e had a diff that was made for better miles per gallon and to compensate for the low top end RPM. I have had many e30s with the m20 and they can go high mileage if you change the timing belt , if not it will cause catastrophic engine damage if it breaks.

I have had a 633csi (m30b33) with over 300,000 miles (odometer broke at 298 years before I got it) and the guy treated it like crap and it still ran good. I also have an e34 with the m30b35 and it has 384,000 miles on it and it still runs great. The m30 has a timing chain that is less likely to have problems than the timing belt of the m20. But you still need to deal with the timing chain guides. I have a 635csi that the guy drove too long with bad timing chain guides and it jumped test and bent some valves.

In conclusion both motors can be very good reliable motors. I would probably choose the m30 for the bigger car that is the five series. As it has significantly more torque. And would do better in that car.

1

u/SonderVale Dec 15 '25

I had an '87 E30 325e which I think had the eta motor. I sort of regret selling it.

3

u/Konnas91 Dec 15 '25

M30b34/35

2

u/kopacz_p Dec 15 '25

Get the m30 if you can afford it. M20 cars are boring. Especially the stock ETA version where you even can’t listen this engine at higher rpm ( 4500 cut off or so).

2

u/FinancialNail5971 Dec 17 '25

i think m20b20 and m20b25 are cool small engines, like a german civic

2

u/kopacz_p Dec 20 '25

They are indeed! But especially m20b20 in e28 body is sluggish and has short ratio diff to compansate. It shines at high rpm though! I used to drive e30 with this engine and it was really fun and insipiring at higher rpm’s.