Stelvio speedometer reading low. - Alfa Romeo Bulletin Board & Forums
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 02-19-2018, 07:55 PM Thread Starter
Registered User
PietroB's Avatar
Join Date: Feb 2017
Location: North Saanich, British Columbia
Posts: 12
Stelvio speedometer reading high.

We took delivery of our Stelvio last August. My wife drives it most of the time ( I drive one of our 3 other Alfas', '68 Berlina, 73 Berlina or the '78 Spider), great vehicle, but I have found that the speedometer reads 11% high at 40 km/hr and 11% high at 90 km/hr. I have spoken with the local Alfa service manager and he says that's 'standard for the industry'. I find this is hard believe that most drivers would put up with mentally converting your correct speed all the time, especially Alfa drivers. Our other 3 Alfas all have speedometers that are within + or - .5% accuracy. We have made tests with radar and speed with other vehicles to confirm the discrepancy. Is there a computer adjustment for this? Is it the tire/rim size (it has 18 inch rims)? Any comments would be appreciated.
Attached Images

Last edited by PietroB; 02-20-2018 at 01:40 PM. Reason: Should have said high instead of low.
PietroB is offline  
Sponsored Links
post #2 of 6 (permalink) Old 02-20-2018, 08:05 AM
Registered User
Vsix's Avatar
Join Date: Jul 2003
Location: Helsinki,Finland
Posts: 758
how did you measure the real speed? in Europe its in law that its not allowed to show lower value than real speed. Max allowed is + 10% so for example in real 100km/h the speedo can show max 114 km/h

-Antti: --ex Alfas:155 2.0 8V '92,155 2.0 16V '96,156 V6 '98,156 V6 '02

Last edited by Vsix; 02-20-2018 at 08:09 AM.
Vsix is offline  
post #3 of 6 (permalink) Old 02-20-2018, 08:55 AM
Push hard and live
Gold Subscriber
DPeterson3's Avatar
Join Date: Apr 2007
Location: Carson City, NV
Posts: 8,859
Same in US. Speedo may not read low, but is allowed to read high. This, in the US, would be a federally mandated warranty if within a certain amount of time since new.

I bet you could find and print out whatever law pertains in Canadjia.

Don P
Carson City, NV

Past Alfas...
59 102 Touring (first Alfa $500 running)
65 Sprint GT (2nd Alfa, $500 daily driver)
102 Sprint (never did anything with it, but wish I had)
74 Berlina (first new car - now certainly rusted into oblivion)
61 Giulietta Spider G-Prod Race Car (where is it now?)
84 Spider Veloce (rarely drove it, so sold it)
86 Quadrifoglio (Dull car - no more 115s for me)
1971 Montreal "The Full Monty". Fair winds and following seas

Current Alfas
59 102 Touring Roadster - restoration complete, enough Alfa for any rational man. Or irrational, for that matter
Oops. Add to the "present" list, 10204 01488, 2000 Touring Roadster project

And past...
Two 1946 Stampe SV4C (c/n 294 "Rocinante" - wife's favorite airplane. RIP), and c/n 235 "La Bon Temps Femme" (gone to a new home, but never forgotten)
Zlin 50LA (+9 -6 gees, titanium spar, 1200 lbs, 260HP rumored to now be in Brazil)
1946 Luscombe 8A
Starduster Too (recently spotted at the Nevada City, CA airport - over 20 years and an entire continent separating it from our stewardship in Binghamton, NY)
1955 Cessna 170B (wife taught me to fly tailwheel in this)

And present...
64 Mooney M20E ("Rambo". My faithful steed for over 40 years) Over 55 years old, and just returned from a trip to Argentina in him
Newest in the fleet
1967 Piper Super Cub on Wipline amphibious floats (a true "all terrain vehicle")
2010 Triumph Thunderbird

You can snap roll an Alfa only one time...
DPeterson3 is offline  
Sponsored Links
post #4 of 6 (permalink) Old 02-20-2018, 09:50 AM Thread Starter
Registered User
PietroB's Avatar
Join Date: Feb 2017
Location: North Saanich, British Columbia
Posts: 12
I may have explained my dilemma incorrectly, when I drive through a 40 km/hr speed limit, my speedometer reads 40km/hr and the radar sign shows 36 km/hr (radar is +/- .5% accurate). Therefore the speedometer is reading 10%+ high. Thanks for your comment.

Last edited by PietroB; 02-20-2018 at 09:57 AM.
PietroB is offline  
post #5 of 6 (permalink) Old 02-20-2018, 01:05 PM
Registered User
Bertiebloke's Avatar
Join Date: Sep 2017
Location: Godalming, Surrey, United Kingdom
Posts: 74
It's normal for modern speedo's to over read by 2-3MPH minimum (3-5kph), maybe more at higher speeds. As alluded to earlier, manufacturers cannot allow speedo to read under (think of the potential litigation with refunds on all those speeding fines.....). They need to allow for drivers with worn vs new tyres and low tyre pressure, all of which reduce rolling radius and thus start to reduce the real speed vs indicated.

If you want a more accurate check than radars there are some phone apps which are quite usable to give accurate GPS speed if you can find a straight level stretch at constant speed - just make sure the phone is safely mounted or get an assistant to manage it.
Bertiebloke is offline  
post #6 of 6 (permalink) Old 02-20-2018, 01:22 PM Thread Starter
Registered User
PietroB's Avatar
Join Date: Feb 2017
Location: North Saanich, British Columbia
Posts: 12
Thank you, I'll try that.
PietroB is offline  

Quick Reply

Register Now

In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

For the best viewing experience please update your browser to Google Chrome