chip help

[arams325]

im looking into buying a mark-d chip for my 87 325is and i have an ecu # of 153 and i need a 173 to instal the chip that i wanted, i can get a 173 ecu for cheap from a friend, but will it work on my car if so will it be a plug n play? thanks for the help guys

[aaron325ix]

from what I understand, the 173 is an updated version of the 153, and they are interchangable. Can anyone back me up on this?

[jlevie]

That would be correct. You can swap the 153 DME for a 173.

[mbbollman]

I have a different chip question. What is the performance/mpg gain differential between the 91 MarkD and the 93 markD. Is it worth the extra $$ per gallon to go for the 93? Thanks

[klayvon]

I'm sure it's worth it, just as long as you can get 93 octane fuel where you are. Out here in California, we only get up to 91 octane. I don't know what it's like out your way though. If you can get 93, I say go for it.

[MarkD]

That would be correct. You can swap the 153 DME for a 173.

Yes the hardware is interchangeable, but the software is NOT.

You can not take a chip from a 153 and run it in a 173, or vice versa.

MarkD