What a difference a Diff makes
Posted: Sun Jun 15, 2014 4:40 pm
For any who may be interested….
See other threads about this for the background but I got hold of a 3.9 diff (thanks, you know who you are!) for my 1098 Traveller daily driver, because I do a lot of motorway/dual carriageways. Had it fitted this week(thanks YOU know who you are!), and WHAT a difference! Even my family who are not very car-aware have noticed it's 'smoother'.
But there's a twist. Turns out I actually had a 4.55 diff under there, so no wonder…
First still feels like first, just slightly less nippy; second lasts longer, third lasts longer still - am sometimes driving at 30 in third now - and fourth, strangely doesn't FEEL that different once I get up to about 60. But that may be just my perception because it also turns out the speedo was previously reading too fast - suspect it was never calibrated for the 4.55 diff - and now it's reading much more accurately when I test it with a GPS speedometer app(which I never did with the 4.55). I've no doubt that steep hills will be slightly more work, but I'm not likely to encounter those day to day. I'll miss the yappy-dog acceleration of the 4.55 but the engine is generally not having to work as hard, which might have a fuel economy benefit.
Are 4.55 diffs in demand? And which cars would they originally have been made for?
See other threads about this for the background but I got hold of a 3.9 diff (thanks, you know who you are!) for my 1098 Traveller daily driver, because I do a lot of motorway/dual carriageways. Had it fitted this week(thanks YOU know who you are!), and WHAT a difference! Even my family who are not very car-aware have noticed it's 'smoother'.
But there's a twist. Turns out I actually had a 4.55 diff under there, so no wonder…
First still feels like first, just slightly less nippy; second lasts longer, third lasts longer still - am sometimes driving at 30 in third now - and fourth, strangely doesn't FEEL that different once I get up to about 60. But that may be just my perception because it also turns out the speedo was previously reading too fast - suspect it was never calibrated for the 4.55 diff - and now it's reading much more accurately when I test it with a GPS speedometer app(which I never did with the 4.55). I've no doubt that steep hills will be slightly more work, but I'm not likely to encounter those day to day. I'll miss the yappy-dog acceleration of the 4.55 but the engine is generally not having to work as hard, which might have a fuel economy benefit.
Are 4.55 diffs in demand? And which cars would they originally have been made for?
