GPS speedometers.

A friend has recently bought an imported Mercedes. Won't be used much, it's for "Sunday best". As an import, the car is LHD and the speedometer is in kilometres per hour, not miles per hour. It'll be rather expensive to replace the speedometer with a one that shows MPH. So he was thinking of augmenting the speedometer with a car-specific GPS speedometer that shows MPH. I don't know a lot about such things. But a few moments googling comes up with:

formatting link
which looks like it would do the job.

Does anyone have any other suggestions, recommendations, useful websites etc?

Reply to
Dennis Davis
Loading thread data ...

I'm not sure about MOT requirements. However, all you really need are a few chinagraph pencil marks on the glass for the important speeds like 30 and 70.

Reply to
Dave Plowman (News)

How would you suggest that an MOT station tests a speedo'?

Reply to
Cecil

There is no requirement for a speedo for the mot. you can buy a small digital display that just picks up from the existing wiring on the car. something like this:

formatting link

Reply to
Mrcheerful

They might notice it has the wrong scale? There are lots of other things they check without the car moving.

Reply to
Dave Plowman (News)

AFAIK the only vehicles that have any sort of check on the speedometer are Class 5. Even then it's only a check that one is fitted, can be illuminated, and is not clearly inoperative.

Chris

Reply to
Chris Whelan

it could be calibrated in knots as far as the mot is concerned, it (ordinary car) does not need one at all (for mot)

Reply to
Mrcheerful

formatting link
You can also buy a little box of trick which recalibrates the speedo by intercepting the pulse and putting out to the speedo a slightly different one with the correction.

Reply to
Harry Bloomfield

formatting link
>>

The cheapest way is to remember that 30mph = 50 kph, 40 mph = 60 kph, 50 mph = 80 kph, 60 mph = 100 kph, and 70 mph = 110 kph. All rounded, but close enough that you'll not get pulled over for speeding.

Depending on the car, it may be possible to have a main dealer reprogram the speedo and odometer, or, if all else fails, speak to your local tachograph centre, who will be able to put a small gearbox on the speedo output from the main gearbox to do the job.

Reply to
John Williamson

Not unless it is an older car (pre-1990?) with a mechanically driven speedo. Most/ all nowadays are electrical impulse driven.

Reply to
Harry Bloomfield

My guess is it would be cheaper to source a UK speedo for that model from a breaker's yard etc. Unless the car is very rare. In which case keep an eye on Ebay. Instruments often get kept long after the rest of the car is gone.

Most cars these days don't have mechanical drives so a gearbox wouldn't work. Of course the OP didn't give the age of the car.

Reply to
Dave Plowman (News)

Our camper is based on a Japanese import, and the conversion included opening the dashboard unit and placing a circular cutout card with the mph scale over the original scale showing kph.

The odometer is still calibrated in km, but this is noted on the MOT.

Reply to
Jim Newman

My Merc '83 a 500sec has a dual scale on the speedo.

Reply to
Rob

Dennis Davis wrote in news: snipped-for-privacy@bath.ac.uk:

All he needs to worry about is actual speed in Miles per Hour while driving. Speedo is not required for MOT, neither is mileage. A simple sat-nav that can show an easy to read speed readout eg. Garmin nuvi 1340 is all that is required. This has the advantage of not needing to modify anything in the car.

Reply to
Tunku

I _think_ after a year in the country it'll need to be registered here for tax, insurance, etc. To do that it'll need to go through the IVA test which will need a speedo calibrated in mph and illuminated by the vehicle's power supply. The tacho's OK in Km though. Kit car people used to get by with a bicycle speedo until they brought the illumination rule in. I think it might also rule out a GPS speedo.

It might need the lights changing to RHD lenses.

This is if it's not already registered here before they brought in all the SVA/IVA rules.

Reply to
Richard Crewe

Assuming the calibration for UK/Euro needles is the same then something like:

formatting link
?

Reply to
Scott M

Only if you want to make your interior look like frightfully chavvy.

Reply to
SteveH

Or just memorize four numbers

30mph = 48.3 km/h 40mph = 64.4 km/h 50mph = 80.5 km/h 60mph = 96.5 km/h
Reply to
johannes

Without conversion the car will not pass MOT requirements , lights will need to be corrected for the dip beam for starters speedo will need to show mph .

If its an electronic speedo then its possible a merc garage may be able to reprogramme the ecu

Reply to
steve robinson

I'm quite surprised why it should not pass MOT. I once had a LHD personal import car (admittedly, some years ago), and it definitely passed MOT. Why does it matter what units the speedo is in? The speedo still records the speed of the car. You can still figure it out.

Reply to
johannes

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.