mookie 0 Posted May 22, 2012 (edited) Hi everyone I have noticed that when comparing the SatNav speed to my indicated speed on my speedometer, that I am overreading by approx 5mph at 30mph (so travelling at 25mph-ish), and just over 10mph at 70mph (travelling at 60mph or just below) - on the gauges, not the SatNav. So I'm driving slower than the gauges say I am. My first thought, and that of a few people I asked, was wheel/tyre size (it's on 17s and low profile rubber). But running it through various online rolling radius calculators, I'm only a few mm bigger than stock 15's on 205/50... and in fact rather than be underspeed compared with my speedo, I should overspeed by about 2mph at an indicated 60mph for example. So my next thought was the gauges. I have DDI illuminated dash gauges (previous owner) and looking at them compared to the installation guide I downloaded, it appears my speedo needle sits too high - rather than be below the 10mph mark, it sits on it. So effectively it's giving me an extra few mph onto my speed before I even move... hence I am driving slower than I think I am by looking at my speedo. My gauges The DDI photo A photo I found on this forum of someone elses DDI's Reading the instruction guide it tells you to remove the needles prior to inserting the illuminated gauges, but are the needles keyed or on some kind of spline fitting? Can I adjust where the speedo needle rests at 0mph or is it dictated by the fitment of the needle into the cluster? If they can be adjusted, is there a good method by which to ensure they are as accurately positioned as possible? If the speedo is slightly out, I'm now worried my temp and petrol are also wrong...! Presumably they should both rest in a certain spot with the engine turned off? Anyone else had a similar issue? Edited May 22, 2012 by mookie Quote Share this post Link to post Share on other sites
Wild-Animal 0 Posted May 22, 2012 Going by memory, the needles are keyed. I cant think of anything that you could do to change where the needle sits Quote Share this post Link to post Share on other sites
mookie 0 Posted May 22, 2012 Ah right, I see. I've just re-read the installation guide again, and it says to 'make a note of the needles positions' before removing them? This is going to bug me something rotten if I can't fix it... Quote Share this post Link to post Share on other sites
dragon green 5 Posted May 22, 2012 Take the needles off, put them about 3mm below the stops,then carefully pull them over the stops ! You do know how to take the needles of I presume ? Quote Share this post Link to post Share on other sites
mookie 0 Posted May 22, 2012 The installation guide says to prise them off by sliding a fork under them and carefully lever them off? Quote Share this post Link to post Share on other sites
dragon green 5 Posted May 22, 2012 The installation guide says to prise them off by sliding a fork under them and carefully lever them off? Correct,once they have been off once,removal is fairly easy ! Quote Share this post Link to post Share on other sites
quicky1980 0 Posted May 22, 2012 actual and dial speeds seem to always differ. You can tweak it as mentioned above but even out of the factory the dials (standard ones) always read faster. Quote Share this post Link to post Share on other sites
V-Dubstar 0 Posted May 22, 2012 Mine's the same, never got round to changing it tho!! :lol: From my experience and trying to remember properly, the temp and petrol gauges seemed to correct themselves, but the speedo one seemed to sit wherever it was placed Quote Share this post Link to post Share on other sites
mookie 0 Posted May 22, 2012 Yeah I was used to the same thing on my various Mk2's, but this is miiiiiiiiiles off! Quote Share this post Link to post Share on other sites