OT Car Insurance

Nov 06, 2012 91 Replies

Nothing to do with power. It's all down to gearing and number of cylinders. 30mph in 4th in my diesel corresponds to about 1200 rpm which is just about okay on the flat but on any incline there's too much vibration. It would be impossible in 6th.

Cars with 6 or more cylinders will generally be happy pulling from lower revs without vibrating.

We live in the middle of a large 20mph zone. 3rd gear is just fine.

Tim

I haven't driven a Mini diesel. The recent ones I have driven have very narrow torque/power bands.

Andy

There are two models . I have no idea how the 1.6 diesel behaves. it looked a little pedestrian to me on paper . The missus found the petrol S a little too lively so when we traded it a compromise was agreed and we got the 2L diesel. She has to drive it most of the time to get to work but I don't want an absolute slug when I need to use her car.

G.Harman

In message , Ferretygubbins writes

Standard requirement for any employee using their car for occasional business use. Volunteers doing charity work can also be affected if they are travelling on charity business - as opposed to the equivalent of to and from work.

Exactly. Top gear is designed to get best results on emission tests first and cruising on the motorway (home and abroad) at 70+ second (that's priorities not gears) Do cars in the German market have higher gear ratio I wonder?

In message , snipped-for-privacy@yahoo.co.uk writes

Maybe you've got clever ant-stall software in the engine management system.

In message , Man at B&Q writes

On a simulator? Who do you work for - McLaren?

I am surprised that any car in the last 30 years can actually do 30mph in top.

In general that's 3rd gear territory I reckon unless you have at least 6 cylinders and a shitload of torque.

Ah!, but you have to define "top" now. I always think of that as 4th or

5th but some now have a 6th and in that 30 is rather not the done thing...

My ancient A6 will do 30 in 4th fine even 5th on the flat, but the younger version 5th isn't too comfortable and 6th its only doing 1000 RPM...

But 30 in 3rd does sound as if its revving away too much..

Well 30mph with 16" wheels works out at around 633rpm at the wheel, I think - 16" diameter = ~50" circumference, so 1267 revs to cover a mile, and 30mph is 0.5 miles per minute.

A 6th gear will normally gear up the engine's output quite a bit, I believe, so to maintain 30mph the engine's going to be running at quite a bit less than 633rpm (the only example I could quickly find was a Corvette, which is 0.56:1 in top, so 354rpm). It certainly wouldn't be happy, if it could even be done at all.

I think that 40mph in 6th on the flat was just do-able on the car that my dad had, but of course there was no sane reason why anyone would want to routinely do that :-) Top was really for 70mph and up...

cheers

Jules

I have 4 cylinders, it's 1500 RPM or so. My wife's car will do it too, and hers only has 3 cylinders. You do have to drop a gear or two (or three!) to accelerate much or go up any hill.

Both 5 speed boxes.

My son's diseasel has a 6 speed box, and 30 is 4th. How much of that is the narrow power band of the highly tuned turbo engine, and how much the

6th gear I couldn't say. I've heard that they gear them now so that 5th is for 56MPH steady speed economy figure, and 6th is for the 75MPH figure.

Andy

On my Land Rover Defender its 4th gear for 30, 5th for 40 and 6th for

50=. Of course no-one seriously does over 70 in a Defender. That way the engine is nicely in its comfort zone at about 1750 rpm. It will drop down to about 1100 but its on the lower limit then.

I don't suppose they teach young drivers about torque curves these days as you very rarely see them on manufacturers literature.

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