Speedo and Cruise about 1 MPH off.

[artinmoTTion]

Hold the tomatoes, I'm going to vote with the Garmin, especially after last night. Those incremental MPH differences can become important when you're, umm...let's say cruising along in the 10 over range on an empty freeway, following your speed in the MFD...
Detroits here.

 

[maverick_uae]

noticed the same thing yesterday.. should check up on my traffic fines :S jeezz! i set it at 80 on a 80kmph road.. those radars flash at 81! aaaaa!!

i'm on detroits too!

 

[joema2]

...VW may be calibrated to the standard 17" wheels and the +1 sizing on our Detroits may be slightly off in diameter...

My speedo reads about 2 mph low at 60 mph. IOW indicated speed is 58, actual speed (via Garmin GPS) is 60. This increases to about 3 mph low at 80 mph -- indicated speed is 77, actual is 80. This is the opposite of most speedos, which typically read a little high. My '10 GTI has 18" Detroit wheels, so I wondered the same thing -- was it calibrated for 17" wheels, and the calibration unchanged from the factory?

Or are there distinct 17" and 18" calibrations from the factory, if the speedo reads low, does this indicate the wheels were swapped by the dealer?

 

[Basil_Fawlty]

My speedo reads about 2 mph low at 60 mph. IOW indicated speed is 58, actual speed (via Garmin GPS) is 60. This increases to about 3 mph low at 80 mph -- indicated speed is 77, actual is 80. This is the opposite of most speedos, which typically read a little high. My '10 GTI has 18" Detroit wheels, so I wondered the same thing -- was it calibrated for 17" wheels, and the calibration unchanged from the factory?

Or are there distinct 17" and 18" calibrations from the factory, if the speedo reads low, does this indicate the wheels were swapped by the dealer?

I think we may have nailed the issue here. Those having this problem are on 18" wheels, and nothing was recalibrated to comp the bigger wheel. This sure seems to be a very reasonable explaination. This is not good, but I presume fixable, through what, a VAG-COM? And as somone else posted, this is good to know and compensate for when on the open highway pushing the allowable radar limits/kindness of the federalies. A State Trooperd ticket costs more for the same speeding offence than does the same ticket from a city police officers pad.

 

[MofoG23]

I think we may have nailed the issue here. Those having this problem are on 18" wheels, and nothing was recalibrated to comp the bigger wheel. This sure seems to be a very reasonable explaination. This is not good, but I presume fixable, through what, a VAG-COM? And as somone else posted, this is good to know and compensate for when on the open highway pushing the allowable radar limits/kindness of the federalies. A State Trooperd ticket costs more for the same speeding offence than does the same ticket from a city police officers pad.

Sorry to rain on everyones parade, but we have the 17" Denvers with the same issue. It was a little worse when we were running our 16" snow wheels / tires.

I drove it the other night and its damn close but still ~ 1 mph off (MFD vs Speedo).

 

[Krazy_Z]

This could be due to the calabration of the machine, the speed display that the cops use may or may not be calabrated correctly thus why they cant give you a ticket off what that says. Unless your speedo dont work i would not trust a GPS to be accurate my gps begins to read slower and slower untill i hook it back up to my computer and update the maps so in about 2 months mine is about 3 to 5 mph off from what my speedo is reading

 

[dstill]

Sorry to rain on everyones parade, but we have the 17" Denvers with the same issue. It was a little worse when we were running our 16" snow wheels / tires.

I drove it the other night and its damn close but still ~ 1 mph off (MFD vs Speedo).

Yer, me too. I've got 17" Seattle's and mine reads 1mph over also. I'm having it looked at in 2 weeks time at the dealer, will post the results, if there is any.

 

[joema2]

...increases to about 3 mph low at 80 mph -- indicated speed is 77, actual is 80. This is the opposite of most speedos, which typically read a little high. My '10 GTI has 18" Detroit wheels, so I wondered the same thing -- was it calibrated for 17" wheels, and the calibration unchanged from the factory?

I think we may have nailed the issue here. Those having this problem are on 18" wheels, and nothing was recalibrated to comp the bigger wheel.

Sorry to rain on everyones parade, but we have the 17" Denvers with the same issue....

The issue was the speedo reads several mph LOW (meaning true speed is several mph HIGH) on some 18"-equipped cars.

Are you saying cars with 17" wheels have that same issue -- speedo reads low, so an indicated 70 mph is actually 73 mph as determined by GPS or radar?

 

[Whafrodamus1]

Are people seriously whining about 1 MPH off?... like ... seriously?

Here's a tip for you. Sell your MKVI.... buy a MKV... and watch while everyone laughs while you get your panties in a bunch.


That's like bitching about "WHY CAN I ONLY RAISE AND LOWER MY SEAT IN INTERVALS OF ONE INCH!? I WANT CENTIMETERS! UNACCEPTABLE."

Cool story, Hansel.

 

[joema2]

Are people seriously whining about 1 MPH off?... like ... seriously?...

No. Some are off significantly more than 1 mph. See previous post.

 

[Whafrodamus1]

No. Some are off significantly more than 1 mph. See previous post.

1 or 2 MPH at ~80 mph is not significant. The only person who reported a significant speedometer issue was talking about his MKV. Seriously though... drive a MKV. About 10% under 40 mph (40 is 36, 80 is 72, etc). That's something to bitch about. I mean I guess being under is better than being over, but 1-2 MPH isn't a big deal. :thumbsup:

 

[TDI110]

1 or 2 MPH at ~80 mph is not significant. The only person who reported a significant speedometer issue was talking about his MKV. Seriously though... drive a MKV. About 10% under 40 mph (40 is 36, 80 is 72, etc). That's something to bitch about. I mean I guess being under is better than being over, but 1-2 MPH isn't a big deal. :thumbsup:

QFT

 

[Antero128]

1 or 2 MPH at ~80 mph is not significant. The only person who reported a significant speedometer issue was talking about his MKV. Seriously though... drive a MKV. About 10% under 40 mph (40 is 36, 80 is 72, etc). That's something to bitch about. I mean I guess being under is better than being over, but 1-2 MPH isn't a big deal. :thumbsup:

Why should my brand new car not show my speed correctly? If my Neon SRT4 showed speed correctly so should my VW GTI. When my GPS, MFD, and speedo all show a different speed it gets a bit annoying. At least the car should agree with itself and not tell me on the MFD that im doing 68 while the speedo says 70.

 

[NEOHMark]

I mean I guess being under is better than being over, but 1-2 MPH isn't a big deal. :thumbsup:

It's not a big deal as long as you know about it - especially if actual speed is lower than indicated. If, however, you like to set your cruise at 10+ on the freeway, and LE sets their radar to 'pop' at 11+ or 12+, then suddenly that 1-2 MPH actual-over-indicated becomes a very big deal.

 

[Whafrodamus1]

Why should my brand new car not show my speed correctly? If my Neon SRT4 showed speed correctly so should my VW GTI. When my GPS, MFD, and speedo all show a different speed it gets a bit annoying. At least the car should agree with itself and not tell me on the MFD that im doing 68 while the speedo says 70.

Crying about it won't fix it. An error of under 2% is perfectly acceptable. You could always trade for smaller wheels, or perhaps clean the sand out of your... umm...