525i M20 vs M50

[Reuben Lim]

What's the skinny on the M50? Have a mati 89 M20 I've put in tip-top shape, EAT chip and all (put in by former owner), and am eyeing a 91 525i and just want to know the pros and cons. Also, is it true I can get away with using the 91 and 93 octane fuels? Have been using 95 leaded, but someone told me I should be regularly using lower octane unleaded and just use the pricier stuff once in a while. Lastly, can I drop in my M20 EAT chip in the M50 If I choose to get it? If not, how much would an M50 chip cost?

[Anton CH.]

Get the m50tu (vanos). After driving my buddies 525i I can say that the new engine is quieter and has better low end torque.

[cary]

Sounds like you are talking about the Eurospec cars, but I can give you a comparision for the US Spec. My wife has a 94 525i and my Sister in law has an 89 525i, both have automatics.

The 94 is much faster. The biggest difference is from a standstill, where the 94 pulls strongly off the line and the 89 doesn't move until about 3000rpms. You can just tell that the M20 motor is overwhelmed by the weight of the e34 chasis. The 94 also has much more power when passing and will walk away from the 89 without a problem.

[Reuben Lim]

Test drive was as you said, the M50 has so much more torque coming off the line, but I suspect the M20 won't be left behind by too much when both cars already at speed. I passed because owner didn't take of the car too well, painted in patches for scratches/dings, interior was really dirty, waves on the dashboard and sidings and all that, car must have been parked exposed in hot sun and all. I guess he didn't love the car, it would show if you did. But only 40 k miles, engine and suspension quite good. It was a tough decision for me, but had to walk away considering repaint/interior refurbish costs. My M20 also US version, got it at 55 k miles, now up to 70 K plus. Aside from its age, my main beef with it is the absence of rear headrests, but the previous owner took care of it, put an EAT chip in, Schnitzer skirts and bumpers, E 39 Mags, and I've improved the sound system too. It goes quite well, a bit of steering wheel shake though past 50.