3.7 diffs?

[moggyadventurer]

Hi,

Can someone explain the benefits of the 3.7 diff? I gave about five of these away in the early 90s.
I see they seem to fetch a premium these days on auction sites.

I guess it is for quieter cruising on motorways etc....increased top speed?

A few friends and I tried a few diff changes in the 80s but found the 3.7 to reduce fuel consumption compared to standard diffs for both 948 and 1098cc. They seemed good on fast straight roads but tended to be crap (excuse the language) for hilly areas were we lived (forever changing gear). I seem to remember getting about 34mph from them compared to about 40 for standards.

[polo2k]

basically it makes all your gears a bit longer, meaning that the same speed requires less revs.

I have a 3.9 to go in mine to try and offset the 13" wheels maybe this would be a good halfway house?

[bmcecosse]

Yes - the whole idea is to reduce fuel consumption.