Speedo inaccuracy
Discussion
I've noticed recently that the analogue and digital speedos are reading differently, but the gap between them is not the same every time I get in the car.
Because they have been reading up to 5mph different from one another (which is quite a lot in my book!), and I did not know which one to believe, I managed to figure out that the digital one is reading correctly by observing speeds at known revs - e.g. I know that in first gear the car idles at 7mph, and in 6th at 2000rpm I will be doing 80.
So, the last time I drove the car the analogue speedo was reading about 5mph low (which could be enough to cost me points on my licence at some speeds), so naturally it's a little concerning. Is there anything I can do to fix this problem or will it need to to and be looked at in a garage?
Because they have been reading up to 5mph different from one another (which is quite a lot in my book!), and I did not know which one to believe, I managed to figure out that the digital one is reading correctly by observing speeds at known revs - e.g. I know that in first gear the car idles at 7mph, and in 6th at 2000rpm I will be doing 80.
So, the last time I drove the car the analogue speedo was reading about 5mph low (which could be enough to cost me points on my licence at some speeds), so naturally it's a little concerning. Is there anything I can do to fix this problem or will it need to to and be looked at in a garage?
The analogue needle on mine under-reads by 1-2 mph at motorway speeds - dodgy I know, but was under the impression they all do that...digital was always spot on (and always used). Well, that was true when I was stock, haven't checked since changing the rear gears (although I have corrected for it in the tune).
KMud said:
The analogue needle on mine under-reads by 1-2 mph at motorway speeds - dodgy I know, but was under the impression they all do that...digital was always spot on (and always used). Well, that was true when I was stock, haven't checked since changing the rear gears (although I have corrected for it in the tune).
The analogue speedo on my CV8 varies from being spot-on to under reading by as much as 6-7 mph when compared with the digital reading. I am also convinced the rev counter at tickover can be inaccurate. Can these issues be corrected or are we stuck with them?GrumpyV8 said:
The analogue speedo on my CV8 varies from being spot-on to under reading by as much as 6-7 mph when compared with the digital reading. I am also convinced the rev counter at tickover can be inaccurate. Can these issues be corrected or are we stuck with them?
There are scalars in the tune (and I believe another scalar in the cluster which can be tweaked cheaply with vzclustermod), but that sounds like it can't be sorted with a simple scalar. No idea I'm afraid, I don't have a problem as far as I know!Interestingly I was looking at this tonight myself. In my E3, the needle always read a few MPH more than the digital read out in the centre console. In my old E1 they were both about the same.
Had a play with a GPS speedometer on my phone tonight and got the following results. When travelling at 50mph by GPS, the digital speedo reads 51/52mph and the needle reads 53mph. If I travel at 50mph by the digital speedo, I see 48mph on the GPS and 51mph on the needle.
I only tried this as I'm fitting 285mm tyres tomorrow replacing my 275mm tyres and wanted to compare the speedo % drift before and after.
Had a play with a GPS speedometer on my phone tonight and got the following results. When travelling at 50mph by GPS, the digital speedo reads 51/52mph and the needle reads 53mph. If I travel at 50mph by the digital speedo, I see 48mph on the GPS and 51mph on the needle.
I only tried this as I'm fitting 285mm tyres tomorrow replacing my 275mm tyres and wanted to compare the speedo % drift before and after.
I've had this before but just put it down to one of those things.
The digital reading is always consistent (1-2mph under reading depending on tyre wear) but the analogue can either match or be a few mph over depending on the position of the moon it seems.
I am impressed by the accuracy though. On all the other cars I've had the speedo has always over read, changes a lot with tyre wear and generally loses accuracy as the miles rack up, but the Monaro's hasn't. Anyone know what Holden have done to make it so accurate and why can't other manufactures do the same!
The digital reading is always consistent (1-2mph under reading depending on tyre wear) but the analogue can either match or be a few mph over depending on the position of the moon it seems.
I am impressed by the accuracy though. On all the other cars I've had the speedo has always over read, changes a lot with tyre wear and generally loses accuracy as the miles rack up, but the Monaro's hasn't. Anyone know what Holden have done to make it so accurate and why can't other manufactures do the same!
So I checked my speedo today against the (albeit not entirely trustworthy) satnav function on my phone and that read exactly the same as my digital speedo. The analogue one was spot on this morning and about 3 mph low this afternoon!
Also, on the motorway this afternoon I found myself being followed by an unmarked police car, so I made sure I followed the digital one as it read higher!
Also, on the motorway this afternoon I found myself being followed by an unmarked police car, so I made sure I followed the digital one as it read higher!
Gassing Station | HSV & Monaro | Top of Page | What's New | My Stuff