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speedo out
Posted: Sun Nov 06, 2011 6:55 pm
by The 3Ts
Hi all i wondered if anyone could give my any ideas as to why my speedo is reading more miles than it should be appox 5mph out
i have the right size tyres 205/65/15 all around so i dont think it is that
Is there anything else that could cause this problem
thanks tony
Re: speedo out
Posted: Sun Nov 06, 2011 8:17 pm
by bigdaddycain
5MPH out which way? Most speedo's are designed to over read a certain percentage...

Re: speedo out
Posted: Sun Nov 06, 2011 8:56 pm
by francophile1947
Your tyres are smaller than the standard 215/65x15.
Re: speedo out
Posted: Sun Nov 06, 2011 9:39 pm
by westonwarrior
loads of bongos are out a bit. not sure why
Re: speedo out
Posted: Sun Nov 06, 2011 9:56 pm
by The 3Ts
what size tyre are you running on
Re: speedo out
Posted: Mon Nov 07, 2011 12:50 am
by Northern Bongolow
francophile1947 wrote:Your tyres are smaller than the standard 215/65x15.

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65% of 215 = more than 65% of 205, someone with better maths skills may say the difference is about ??? the difference you have.
Re: speedo out
Posted: Mon Nov 07, 2011 7:12 am
by gasace
Northern Bongolow wrote:francophile1947 wrote:Your tyres are smaller than the standard 215/65x15.

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65% of 215 = more than 65% of 205, someone with better maths skills may say the difference is about ??? the difference you have.
The 215 refers to the width of the tyre, the circumference is the important size that is set by the size of the rim (15) and the tyre profile (65) so they should be as standard
Re: speedo out
Posted: Mon Nov 07, 2011 1:52 pm
by francophile1947
The 205/65x15 tyres that you have are 1.97% smaller than the standard 215/65x15 (see
http://www.tyresave.co.uk/tyresize.html). Therefore, your speedo will be reading faster than you are actually travelling. Even on 215/65x15, I found that my speedo was slightly faster than actual speed, which is common with most vehicles, and means you don't get done at speed cameras. I now have 225/55x17 fitted and, per the satnav, the speedo is spot on
