It's been a while (C5 Adventure)

Tell us your ongoing tales and experiences with your French car here. Post pictures of your car here as well.

Moderators: RichardW, myglaren

User avatar
daviemck2006
Donor 2020
Posts: 4952
Joined: 04 Dec 2010, 19:45
x 333

Re: It's been a while (C5 Adventure)

Post by daviemck2006 »

Steves car did not have the correct wheels on it, it should have had alloys but had steels and trims. I think his tyres were 195/65x15 which was one size too small. I suspect that his wheels came off an lx trim c5 either a 1.8 petrol or a 2.0 90 rather than a 110 which his car is. That would have meant his wheels turning faster for a given speed so his speedo reading fast. Considering most speedos read slightly fast anyway, my leon says 33 when the sign coming into the town says 30, the xantia was about correct with those wheels on, but 3mph fast with the standards on.

Sent from my SM-T585 using Tapatalk

Hell Razor5543
NOT Alistair or Simon
Posts: 11549
Joined: 01 Apr 2012, 09:47
x 1325

Re: It's been a while (C5 Adventure)

Post by Hell Razor5543 »

I know that the legal requirement is that the speedos can have a tolerance one way (so they can read that you are travelling faster than you actually are), but no tolerance the other way (so it must NOT show slower than the actual speed). This assumes that everything on the car is how the manufacturer specified.

User avatar
daviemck2006
Donor 2020
Posts: 4952
Joined: 04 Dec 2010, 19:45
x 333

Re: It's been a while (C5 Adventure)

Post by daviemck2006 »

I think that most of the cars i have owned since they put the sign that shows your actual speed up says 32 or 33 when it flashes 30. I know also that last week driving the activa down the road i was sitting at bang on 80 on the speedo and my wee garmin sat nav said 73. I think thats the way its supposed to be so if you were sticking tp 70 on the speedo you are well within the limit. If it was the other way everyone would be speeding! By the way i am not advocating that everyone drives at an indicated 80 lol

Sent from my SM-T585 using Tapatalk

User avatar
Stickyfinger
Donor 2016
Posts: 10006
Joined: 28 Mar 2013, 22:05
x 735

Re: It's been a while (C5 Adventure)

Post by Stickyfinger »

daviemck2006 wrote: By the way i am not advocating that everyone drives at an indicated 80 lol

I am !..................... :)

Hell Razor5543
NOT Alistair or Simon
Posts: 11549
Joined: 01 Apr 2012, 09:47
x 1325

Re: It's been a while (C5 Adventure)

Post by Hell Razor5543 »

Stickyfinger wrote:
daviemck2006 wrote: By the way i am not advocating that everyone drives at an indicated 80 lol

I am !..................... :)
You would, but not all of us have a car that could out-corner a housefly in a room full of voracious bats!
Last edited by Hell Razor5543 on 21 Mar 2017, 08:51, edited 1 time in total.

User avatar
daviemck2006
Donor 2020
Posts: 4952
Joined: 04 Dec 2010, 19:45
x 333

Re: It's been a while (C5 Adventure)

Post by daviemck2006 »

With decent grippy tyres, which it will get, the 205 wont be far behind the activa in the cornering stakes, but with 155x13 debica budget shyte ditchfinders its like being on castors. They were probably ok for the 84 year old lady that never drove out of Crewe!

Only 80 Sticky?

Sent from my SM-T585 using Tapatalk

Trainman
Donor 2018
Posts: 2585
Joined: 21 Aug 2009, 11:58
x 12

Re: It's been a while (C5 Adventure)

Post by Trainman »

Ladies, Ladies, Ladies......... :rofl2:

Changing the wheels has NOT changed the speedo, from the 'speed check' using the satnav, it's still reading about 10% under what's shown on the Satnav. In other words, going from 15's to 17's has made no difference whatsoever.

Now, the version of Lexia, I have (3.45) The only one that will talk to the car, won't let me change the wheel sizes, I'm getting a later version of Lexia sent to me, that I know does allow me to change wheel sizes, I'm hoping that this may help, but not being as technical as you rabble....... :oops: I'll have to wait and see

Hell Razor5543
NOT Alistair or Simon
Posts: 11549
Joined: 01 Apr 2012, 09:47
x 1325

Re: It's been a while (C5 Adventure)

Post by Hell Razor5543 »

Sorry, Steve, I did not make my meaning clear. I was not thinking about the size of the wheels, but more the circumference of the tyres. If your C5 had been set up to have tyres with a circumference of 1 meter then (obviously) when the wheels rotate once the car will have moved by 1 meter. However, if larger tyres had been fitted (say, with a circumference of 1.1 meters) the car would move 1.1 meters per rotation, but the electronics would believe it had moved by 1 meter.

elma
Posts: 3745
Joined: 13 May 2007, 02:17
x 213

Re: It's been a while (C5 Adventure)

Post by elma »

Dash speedos have to read at least 1.5% high by eu regulation.
Most are set a bit higher than this for a safety margin.
My Xantia for example is about 4% high from my (very rough) calculations.
So I do drive at 75mph, indicated, knowing I'm really doing 70mph and speed cameras do not go off.

Hell Razor5543
NOT Alistair or Simon
Posts: 11549
Joined: 01 Apr 2012, 09:47
x 1325

Re: It's been a while (C5 Adventure)

Post by Hell Razor5543 »

Yes, but Steve's speedo is reading LOW, showing 46MPH when he is actually travelling at 50MPH. That is the problem.

elma
Posts: 3745
Joined: 13 May 2007, 02:17
x 213

Re: It's been a while (C5 Adventure)

Post by elma »

What is the oem tyre size for his car?

Hell Razor5543
NOT Alistair or Simon
Posts: 11549
Joined: 01 Apr 2012, 09:47
x 1325

Re: It's been a while (C5 Adventure)

Post by Hell Razor5543 »

On MY C5 the label states 215/55/R16 (and my tyres match this). When I have compared the indicated speed to the Sat Nav speed I have found that they match (within 1MPH).

User avatar
Mandrake
Posts: 8283
Joined: 10 Apr 2005, 17:23
x 355

Re: It's been a while (C5 Adventure)

Post by Mandrake »

Has the car perhaps had a gearbox swap with a gearbox from a different car with a different final drive ratio ? That might also affect the reading depending on where the sensor is.

A lot of gearboxes come in different versions with different final drive ratio that are otherwise interchangeable.

Hell Razor5543
NOT Alistair or Simon
Posts: 11549
Joined: 01 Apr 2012, 09:47
x 1325

Re: It's been a while (C5 Adventure)

Post by Hell Razor5543 »

I believe (but I do NOT know) that the C5 uses the ABS system to calculate the speed, and not a drive from the gearbox itself. If I am right (and that is a big IF) the gearbox would not have any input to the speedometer of the C5.

If the speedometer itself is faulty it appears simple to replace the stepper motor, according to the instructions in the following link;

http://www.roadtestreports.co.uk/qanda/88959/

Trainman
Donor 2018
Posts: 2585
Joined: 21 Aug 2009, 11:58
x 12

Re: It's been a while (C5 Adventure)

Post by Trainman »

OK the tyres fitted to the car when I bought it were 195/65R15 the current wheels are 205/50 17