Mileage query.

This is the place for posts that don't fit into any other category.

Moderator: RichardW

Northern_Mike

Mileage query.

Post by Northern_Mike » 05 Apr 2014, 20:27

The speedo on my V6 is consistently 10% out.

Does this mean then, that instead of the indicated 138,800 miles it's actually only done 124,200 miles?



Sent from my GT-I9505 using Tapatalk

User avatar
Xaccers
Posts: 7654
Joined: 08 Feb 2007, 00:46
x 3

Re: Mileage query.

Post by Xaccers » 05 Apr 2014, 21:28

Depends.
You'd have to check it by driving at a constant speed for an hour and check if you've done that many miles or less on the odometer.

rory_perrett
Posts: 715
Joined: 05 Nov 2001, 20:18

Re: Mileage query.

Post by rory_perrett » 05 Apr 2014, 22:40

My speedo is about 7% out and the mileage is out by the same so I guess my 306,000 miles is really only 285,000!

Eddie Nuff
Posts: 476
Joined: 15 Nov 2012, 21:31
x 34

Mileage query.

Post by Eddie Nuff » 06 Apr 2014, 10:59

The law states that any vehicle under 3.5t must have a 10% tolerance on the speedo. The tolerance is one way only showing that you are traveling faster than you actually are. Therefore at 50mph it's quite possible that you could be doing 45mph.

Any vehicle over 3.5t and fitted with a tachograph is only allowed a tolerance of 4%. Therefore at 50mph this type of vehicle could be doing 48mph.

Northern_Mike

Re:

Post by Northern_Mike » 06 Apr 2014, 16:22

Eddie Nuff wrote:The law states that any vehicle under 3.5t must have a 10% tolerance on the speedo.
No, it doesn't. It states a speedo is *allowed* to over-read by 10% but not under-read. There is no requirement for it to over-read. If that were true, my Berlingo, which is 1mph out throughout, would be illegal..

"The Motor Vehicles (Approval) Regulations 2001[12]... etc .. etc... As with the UNECE regulation and the EC Directives, the speedometer must never show an indicated speed less than the actual speed. However it differs slightly from them in specifying that for all actual speeds between 25 mph and 70 mph (or the vehicles' maximum speed if it is lower than this), the indicated speed must not exceed 110% of the actual speed, plus 6.25 mph"

Eddie Nuff
Posts: 476
Joined: 15 Nov 2012, 21:31
x 34

Re:

Post by Eddie Nuff » 08 Apr 2014, 07:44

Before you get your Cherry Picker out it would be wise to read the whole post:-
Eddie Nuff wrote:The law states that any vehicle under 3.5t must have a 10% tolerance on the speedo. The tolerance is one way only showing that you are traveling faster than you actually are. Therefore at 50mph it's quite possible that you could be doing 45mph.

Any vehicle over 3.5t and fitted with a tachograph is only allowed a tolerance of 4%. Therefore at 50mph this type of vehicle could be doing 48mph.

Northern_Mike

Re: Mileage query.

Post by Northern_Mike » 08 Apr 2014, 10:06

You would be wise to quote the regulation direct from the government legislation website, as I did. Not make it up as you go along.

Oh, and learn the meaning of the word "must'..

Sent from my GT-I9505 using Tapatalk

User avatar
Xaccers
Posts: 7654
Joined: 08 Feb 2007, 00:46
x 3

Re: Mileage query.

Post by Xaccers » 08 Apr 2014, 10:10

You would all be wise to wind your necks in and learn to be grateful that information has been offered up for polite discussion. This is not the place for nit picking or badly veiled put downs

Sl4yer
Posts: 847
Joined: 12 Apr 2003, 04:29
x 1

Re: Mileage query.

Post by Sl4yer » 10 Apr 2014, 01:20

Not a Citroen, but anyway...

I used to have a company Leon (near to the end of the original model, 150hp diesel FR, and a fantastic car!). I always thought the speedo overread, and that was proved by satnav. Interestingly though, if the cruise control was set to hold a certain speed (say 60mph, set from the speedo) the trip computer would record an average speed lower than that set. A speed which would correspond with the satnav readings. The mileage reflected the true reading, not the speedo reading. So, basically, the computers knew what the car was doing, but the speedo displayed something different. The difference was large - indicated 90mph was actually 82.

I'd bet most 'modern' cars (where the speed signal is digital, rather than via a cable) are similar, and the mileage will be correct.

James