125I E82 advice/show

Captain_Stealth

Well-known member
ok will post table when I am home

Is your car a manual or an auto.

Also if your objective is to lower the revs you would need what they call a higher diff ratio (this can be confusing as higher actually means a lower number lol).

With doing this your fuel consumption might go up on town driving cause you would need give more gas to accelerate, but you will benefit on the freeway.

catch 22 situation unfortunately
 

golfer23

Active member
its an auto....i dont think it would be drastic in town driving, shouldnt be? how much more gas? must be marginal.
 

Captain_Stealth

Well-known member
e8x final drives_3992551438.png


sometimes bmw does change things so just double check on the ratios according to the label on the diff.

I cannot comment on how a diff change will effect on an auto
 

Captain_Stealth

Well-known member
if yours is a 3.73 ratio and you change to a 3.64 it wont be much of a change, I would look at maybe a 3.46 from a 130i manual. I think anything more that a 3.46 ratio is going to impact your performance quite a bit

Manual and Autos use the same style diffs as long as the casings is the same, most of the time you just need to change the propshaft coupler to get them to fit
 

golfer23

Active member
thanks for your help! thats what im going to start looking for.
What do the diffs go for price wise?
 

Captain_Stealth

Well-known member
your cheapest option would be facebook of ppl who are stripping their cars

I would look at e9x and e8x that came with 6 cylinder motors the ratio is on a label, no label dont take it !

The part numbers dont always match up on the diffs casing so make sure it has the label to confirm

If you going to a scrapyard I would expect to pay R3000-4000
 

golfer23

Active member
we did a comparison between my 125i auto and a manual 130i.
at 120km/h:
130i - 3000revs there about
125i - 2450/2500 revs

at 100km/h:
130i - 2400 revs
125i - 2000 revs

so now im thinking leave things as be, as what would a diff swap do if added?
 
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