speed check

[phil smith]

since i got the focus it didnt seem i was going as fast as the speedo said, well yesterday i was driving through 30mph zone with a smiley face speed checker, speed checker said i was doing 27mph, speedo said i was doing 34mph, why such a differance????, i went home and got in my navara and drove through the 30mph zone again, both speed checker and speedo on navara both read 30mph, so why would the focus read out ??

thanks phil

[Stoney871]

It is standard practice for car speedos to over read by about 10%.

Sent from my SM-G930F

[Joss max]

My Focus does the same Phil. Your not alone.

[TomsFocus]

They all over read a bit but 34 at 27 does seem a lot.  Have you got the correct sized wheels and tyres on there?

[Ryan_Tango]

Mines out by 2, as Tom said it could be incorrect tyres or different sized wheels

[Russ]

What makes you think the 'speed checker' is set 'bang on'?

[biff55]

compare your cars speedo reading against the current speed display on a tomtom or similar standalone satnav.

satnav will give a measurement in real time using gps lock so should be fairly accurate and wont be affected by any wheel / tyre combinations.......

 

;-)

[spurswes]

1 hour ago, biff55 said:

compare your cars speedo reading against the current speed display on a tomtom or similar standalone satnav.

satnav will give a measurement in real time using gps lock so should be fairly accurate and wont be affected by any wheel / tyre combinations.......

 

;-)

That's true I think,someone I know said satnavs are pretty spot on

[Russ]

http://www.raccars.co.uk/news/why-your-sat-nav-makes-your-drive-faster

[phil smith]

12 hours ago, TomsFocus said:

They all over read a bit but 34 at 27 does seem a lot.  Have you got the correct sized wheels and tyres on there?

wheel and tyres are 195/55/15

[phil smith]

10 hours ago, Russ said:

What makes you think the 'speed checker' is set 'bang on'?

because i also drove past it in my transit and nissan navara, both at 30mph and speed checker read 30mph so i dont think its the speed checker

[Stoney871]

Shouldn't the tyres be 16's?

Sent from my SM-G930F

[JW1982]

7 hours ago, phil smith said:

wheel and tyres are 195/55/15

Ford prescribes 2 different tyre sizes for the focus MK1 with 15 Inch wheels.

195-55-15

195-60-15

However the 195-55-15 tyre size should only be installed on low powered versions like the 1.4 Zetec engine. All other versions should have the 195-60-15 tyre size. 

These large deviations can occur if the car originally had the 195-60-15 tyre size and someone changed these to the 195-55-15 tyre size without changing the programmed tyre size. To avoid these deveations it will be necessary to reprogram the PCM using the correct tyre size.

[phil smith]

27 minutes ago, JW1982 said:

Ford prescribes 2 different tyre sizes for the focus MK1 with 15 Inch wheels.

195-55-15

195-60-15

However the 195-55-15 tyre size should only be installed on low powered versions like the 1.4 Zetec engine. All other versions should have the 195-60-15 tyre size. 

These large deviations can occur if the car originally had the 195-60-15 tyre size and someone changed these to the 195-55-15 tyre size without changing the programmed tyre size. To avoid these deveations it will be necessary to reprogram the PCM using the correct tyre size.

just looked on the ford focus 1.8 tddi 2001 specs and it says front and rear tyres should be 185/65/r14, i have got 195/55/15 on front and rear, would that make so much differance

thanks phil

[JW1982]

The base Ghia version did have 14 inch steel wheels with 185-65-14 tyres. Many people ordered the optional alloy (Ghia) wheels which are 15 Inch.

Usually the vehicle specifications including the original tyre size can be found on the Ford ETIS website but unfortunately this information is only accesible for more recent vehicles.

It is not possible to check the programmed tyre size of the focus mk1. You either have to live with it or go to a Ford dealer and let them reprogram the PCM with the correct currently installed tyre size.

[phil smith]

2 minutes ago, JW1982 said:

The base Ghia version did have 14 inch steel wheels with 185-65-14 tyres. Many people ordered the optional alloy (Ghia) wheels which are 15 Inch.

Usually the vehicle specifications including the original tyre size can be found on the Ford ETIS website but unfortunately this information is only accesible for more recent vehicles.

It is not possible to check the programmed tyre size of the focus mk1. You either have to live with it or go to a Ford dealer and let them reprogram the PCM with the correct currently installed tyre size.

think i will just live with it then, and go with the flow of traffic i guess, lol

thanks phil