speedo

Need technical Q/A then you're in the right place

Moderator: martauto

User avatar
martauto
E30 Zone Team Member
E30 Zone Team Member
Posts: 6215
Joined: Wed Aug 31, 2005 11:00 pm
Location: leeds

Post Tue May 16, 2006 5:55 pm

Hi guys,
Ive just changed my tyres from 195/60/14 To 195/70/14.
The 70`s are quite larger in diameter than the sixties, so , must have an effect on the final road speed even though the speedo will read the same.
Any one got any ideas about re-calibrating or not.
The tyres were given to me by a buddy (not bad eh) and look better on mine than the 60`s.
So what do you think?
Is it worth changing anything on the speedo or just leave it alone??

Cheers, Mart. :D

316 auto 1986
Top
EThreezero
E30 Zone Camper
E30 Zone Camper
Posts: 1007
Joined: Mon Jun 20, 2005 11:00 pm
Location: Central Caledonia

Post Wed May 17, 2006 12:39 am

Turn the profile guage on the back of the clocks to 70 winkeye :mad:
Image

*******MERC E240 BREAKING..1998...LEATHER...ALL PARTS*******
Top
Zayyan
Engaged to the E30 Zone
Engaged to the E30 Zone
Posts: 6385
Joined: Wed Jan 12, 2005 11:00 pm
Location: Aylesbury

Post Wed May 17, 2006 12:50 am

Seeing as the majority of E30 speedos overread quite significantly (one of mine by 10%) I'd borrow a sat nav from someone which shows your current speed, and see how far out it is throughout the range.

Have to ask though - what's the reason for the balloon tyres? Going rallying?
Image
Top
Chris-W
E30 Zone Team Member
E30 Zone Team Member
Posts: 7219
Joined: Tue May 24, 2005 11:00 pm
Location: South Cheshire

Post Wed May 17, 2006 8:34 am

I wouldn't be concerned about the speedo readings with that change to be honest.

And don't knock 'balloon' tyres - they'll be making a comeback soon. You'll see!
Top
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49360
Joined: Mon Jan 10, 2005 11:00 pm

Post Wed May 17, 2006 9:27 am

Chris-W wrote:I
And don't knock 'balloon' tyres - they'll be making a comeback soon. You'll see!
Fully agree, these things are only fashion and go around in cycles.
I've been around long enough now to see wheels shrink from 19" down to 10" and now back up again.
Top
User avatar
orangecurry
E30 Zone Addict
E30 Zone Addict
Posts: 2518
Joined: Mon Apr 11, 2005 11:00 pm
Location: West Sussex

Post Wed May 17, 2006 9:57 am

martauto wrote:Hi guys,
Ive just changed my tyres from 195/60/14 To 195/70/14.
The 70`s are quite larger in diameter than the sixties, so , must have an effect on the final road speed even though the speedo will read the same.
Any one got any ideas about re-calibrating or not.
The tyres were given to me by a buddy (not bad eh) and look better on mine than the 60`s.
So what do you think?
Is it worth changing anything on the speedo or just leave it alone??

Cheers, Mart. :D

316 auto 1986
the 195/60s you had were already too 'small' to give 'accurate' readings, as the 'correct' size is 195/65
Therefore running 195/70s you are just as wrong as before you changed, but in the other direction of wrongness.

The actual difference in rolling diameter is approx 2cm from 60 to 65, and another 2cm from 65 to 70

(Brian you can't be THAT old - they were last running 19" in the 1920s :twisted: )
Top
User avatar
martauto
E30 Zone Team Member
E30 Zone Team Member
Posts: 6215
Joined: Wed Aug 31, 2005 11:00 pm
Location: leeds

Post Wed May 17, 2006 7:07 pm

Cheers guys,loads of good info there :D
Why the "balloon tyres"?
I had all four given and the mot is due soon, right answer?

Mart. winkeye
Top

Return to “E30 Technical Help”