Really short gearing, or is it just me?

finnjb · 10th March 2022, 20:07

Hi all, I've had my 2001 75 1.8 manual for a couple of months now and it's been used a fair bit, gone up to Wolverhampton (I'm in Bristol) and I've noticed a couple of things about it, the main one of those things being the gearing. Why is it so short? At 70mph it's doing about 3500rpm, and it's a bit annoying. I love it, but at 120mph (private road yada yada) it's basically on the limiter. I was talking to someone with a 1.4 25, and they were saying that the gearing is strangely long on it. Is it possible that someone's put the wrong gearbox in my car or do all 75s just have really short gearing, or is it just that I'm used to big Mercs which do autobahn speeds at really low rpm?

SD1too · 11th March 2022, 06:55

Quote:

Originally Posted by finnjb

Why is it so short? At 70mph it's doing about 3500rpm ...

Hi Finn,

Your gearing is correct for your 1.8 manual. The ratios are chosen to complement the engine power and torque characteristics and to achieve reasonable fuel consumption.

Simon

RobH67 · 11th March 2022, 07:36

According to my MG ZT brochure, gearing is as follows:

1.8 120 - 20.7 mph per 1000 rpm in 5th so 3380 rpm at 70.
1.8 160 - 22.2, 3150 rpm
2.5 160 - 23.5, 2975 rpm
2.5 180 auto - 28.1, 2490 rpm
2.5 190 - 21.0, 3333 rpm
2.0 diesel manual - 29.2, 2400 rpm
2.0 diesel auto - 31.7, 2200 rpm

suzublu · 11th March 2022, 09:15

What's 70mph look like 😁

Sent from my SM-A326B using Tapatalk

Yorkshire GOC · 11th March 2022, 11:15

My 1.8t revs dead on 3000 at 70 mph.

trikey · 11th March 2022, 11:45

Have you got 40 series tyres fitted?

GJ53 DGO · 11th March 2022, 18:29

Quote:

Originally Posted by Yorkshire GOC

My 1.8t revs dead on 3000 at 70 mph.

You beat me to it. When I had a new engine fitted I was told not to take her over 3000rpm for the 1st 1000 miles, fortunately for me I had a trip down to London soon after so got most of my 1000 miles done in a very short space of time at a steady 70mph.

finnjb · 11th March 2022, 21:03

Quote:

Originally Posted by SD1too

Hi Finn,

Your gearing is correct for your 1.8 manual. The ratios are chosen to complement the engine power and torque characteristics and to achieve reasonable fuel consumption.

Simon

Thanks, so basically there's not really anything I could do to make the gearing just a tiny bit longer, like no slightly longer factory final drive or anything?

SD1too · 12th March 2022, 07:01

Quote:

Originally Posted by finnjb

... like no slightly longer factory final drive or anything?

Thanks for your reply Finn.
If you did that your acceleration would suffer. If it really bothers you I'd say your best bet is to look out for a nice 1.8 Turbo which will give you 3,000 rpm at 70 mph.

Simon

10th March 2022, 20:07	#1
finnjb Newbie Rover 75 Saloon Join Date: Jan 2022 Location: Bristol Posts: 28 Thanks: 3 Thanked 18 Times in 6 Posts	Really short gearing, or is it just me? Hi all, I've had my 2001 75 1.8 manual for a couple of months now and it's been used a fair bit, gone up to Wolverhampton (I'm in Bristol) and I've noticed a couple of things about it, the main one of those things being the gearing. Why is it so short? At 70mph it's doing about 3500rpm, and it's a bit annoying. I love it, but at 120mph (private road yada yada) it's basically on the limiter. I was talking to someone with a 1.4 25, and they were saying that the gearing is strangely long on it. Is it possible that someone's put the wrong gearbox in my car or do all 75s just have really short gearing, or is it just that I'm used to big Mercs which do autobahn speeds at really low rpm?

11th March 2022, 11:15	#5
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,063 Thanks: 1,842 Thanked 623 Times in 469 Posts	My 1.8t revs dead on 3000 at 70 mph. __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

11th March 2022, 11:45	#6
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,763 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	Have you got 40 series tyres fitted? __________________ Lest we forget..

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

11th March 2022, 07:36	#3
RobH67 Newbie MG ZT-T 180 Join Date: Sep 2020 Location: Gloucester Posts: 25 Thanks: 1 Thanked 11 Times in 7 Posts	According to my MG ZT brochure, gearing is as follows: 1.8 120 - 20.7 mph per 1000 rpm in 5th so 3380 rpm at 70. 1.8 160 - 22.2, 3150 rpm 2.5 160 - 23.5, 2975 rpm 2.5 180 auto - 28.1, 2490 rpm 2.5 190 - 21.0, 3333 rpm 2.0 diesel manual - 29.2, 2400 rpm 2.0 diesel auto - 31.7, 2200 rpm

11th March 2022, 09:15	#4
suzublu This is my second home rover 75 1.8 vvc club se wedgwood blue Join Date: Aug 2009 Location: Seaton Carew Posts: 26,912 Thanks: 65 Thanked 7,142 Times in 4,642 Posts	What's 70mph look like 😁 Sent from my SM-A326B using Tapatalk