Hi. I used to own an XJ8 so recently I had a chance to buy a nice XE 35t used. After a week of driving I've realized the speedometer is off by 5 mph at 65. Less at lower speeds. More at higher speeds. I checked and the tires match factory spec. Is this a common problem?

I tried searching the forum but didn't find anything? Online Google says its an issue but no real resolution.

Any help is appreciated

 

Mine reads 2 mph over at 30 mph, so 32. We have these roadside speed indicators here in the UK in urban and village locations which I checked against, Nothing to worry about unless it is under-reading. Its useful here where there is an army of police and officials trying to find fault and make money out of it.

 

There is no specific speedometer (Instrument Pack) listed for the US market so I expect the unit will comply with UK Construction & Use Regulations. These specify the speedometer:

1. must never under report a vehicle's speed
2. must never over report by more than 110% of the actual speed + 6.25 mph

That is a very wide range and many will have noticed the speed indicated by their SatNav is often significantly less than displayed on the vehicle speedmometer.

Using your example of 60 mph. Your speedometer can never read less than 60 mph but may read up to 72.25 mph. As another actual example, my XK indicates 76 mph at 70 mph.

Graham

 

Ok, thanks for your responses, they seem consistent with what i read elsewhere.

I guess I'm just not used to that. I drive alot, I've driven alot of cars and I just haven't had to even consider this before. To further complicate I often speed, so now I have introduced a level of uncertainty that I just never had to worry about before.... because its not like I'm gonna slow down... I just bought a sleek 6 cylinder turbo 😆

 

Mine reads 2 mph high at normal speeds.
(It's a supercharger, not a turbo on your engine.)

 

Ah. Thanks. Yeah guess I knew that, just being loose with words.... but **** with numbers, engineering occupational Hazzard 😆

 

In France and, probably, the rest of the EU speedometers are set roughly 7% fast. So 52 on the clock for 50km/hr, 74 for 70 up to about 138 for 130 km/hr on the autoroute. These figures vary from manufacturer to manufacturer. Check with a reliable satellite speedometer on yout iPhone. Actual and speedometer reading speeds are a bit +/- on the Jaguar range because the cruise control only goes up or down by 2 km/hr per click. Exercise caution and if the Gendarmes stop you don’t mention my name!

 

Looks like the good news is the speedo thing is consistent. I haven't been to France in years, but i don't remember the speeds being enforced too strictly, you must be quite the driver to have a reputation like that 😁

 

No, I’m a good boy I am. But nowadays the Gendarmes are on the ball. 20 km/hr over the limit they can and do take your license and in serious cases can impound your car. These are not the good old days.