Changing from 4.22 diff to 4.55

[bigginger]

In case you're thinking "ah, but weight/wind resistance would account for all that", I also run a 1275 in a commercial, effectively doubling the power available. Guess what the top speed is... Ooooh, 70!

[Packedup]

Depends on the car. mk2 Cav 1.6 seemed to creep a little higher in 4th, 1.8i was better in 5th (indicated top end of about 138 before the engine dumped its oil ). My one and only "powerful" car, a 2l Rover, certainly managed a higher top end in 5th than 4th. But as that was (indicated) over twice the maximum limit in this country, it's all a bit pointless to argue over really!

I've had various Minis out of revs before in top, most of them either standard or very mildly tuned, and managed to get various Triumphs (and even a Skoda) into the red in top. I think with especially old British cars there was a tendency to undergear them for outright speed/ cruising, in favour of better acceleration. Personally I prefer something a little taller geared so I can use the torque of the motor instead of hunting the powerband, makes for a more relaxed drive too.

[Onne]

That is why I'd rather have a 4,22, less revs at 60 mph, so lower fuel consumption.

all the cars I have owned were a lot faster in 5th than 4th. Outrevving again! 110mph in the Celica, guzzling fuel as if it were free.

I did 155 miles, using a little over 50 litres of super unleaded. Getting a wing from the other side of the country. Only took me 1,5 hour btw.

[paulk]

Onne !

14mpg!!!! You've not even got any hills to blame it on.

[ianselva]

Most cars of the fifties and sixties were geared for driving on A roads and the occasional dual carriageway and so appear undergeared on todays open roads. I always try to fit a higher ratio diff if possible , depending on the tune of the engine and found that a standard 1098 would pull a 3.9 diff qute easily . I will admit that there is only myself and at most one passenger and we don't have a lot of serious hills round here.However for most of the time it was quiter, especially at speed and didn't seem to effect acelleration noticeably.

[Cam]

Aye Carumba! Was there a hole in the tank! I think perhaps Onne meant it was 155 miles AWAY and it used just over 50 litres round trip (a slightly more respectable 28 MPG!).

[Onne]

I didn't. I used just over 80 litres on the return trip, had a lot of traffic on the way there.
14 MPG is not too bad is it? A Rolls only does 12mpg

[bigginger]

Well, if you were doing 110 all the way you'd expect it to be a BIT higher, but 14MPG? Fair enough on a turboed 3 litre (he guessed..) but a Celica?

[Onne]

Twin carbd Celica, with very badly adjusted carbs.
that is two twin stage Solexes. Still madness, I know.

And this all to get a wing for my car, as someone sent me the wrong side! The guy did give me a tenner for fuel. Pity I spent £75

[bigginger]

[Onne]

Ooh well, its only 4,25 % of the amount spent on my little misfortune

[bigginger]

!