My speedometer is off by a ratio of .94

[Fleetw00d]

Before you spend the $$ and replace the VSS, do some more troubleshooting. Did you check if the odometer is reading correctly or if it is also off by .94? You can check this against a GPS or highway mile markers (assuming they are correct). If you travel 10 miles and the odometer shows 10.6, then your odometer matches your speedometer and it may be an issue with the tires. If the odometer shows 10 miles, then the issue may just be the speedometer. Do me another favor, measure the distance from the ground to the exact center of the end of the axle at both front wheels. Also, what specific tire (manufacturer and model) and size did you put on? Stock 93 SE, correct? Do you recall what the engine rpm is when the speedo indicates 80?

[islandhopper]

....

I really want to go for a bike ride. More than anything....

Fixed

Im going to replace my VSS asap because my speedo and odometer are slightly off. I'll let you know if it helps either of them, if you haven't replaced yours by then.

[Fleetw00d]

Im going to replace my VSS asap because my speedo and odometer are slightly off. I'll let you know if it helps either of them, if you haven't replaced yours by then.

How much is "slightly"? Don't waste your money until you've done some troubleshooting and are sure there is a problem.

[islandhopper]

How much is "slightly"? Don't waste your money until you've done some troubleshooting and are sure there is a problem.

At 20mph my GPS reads at 26. At 35 its dead on with my GPS. And when my GPS says 55MPH my speedo reads 69mph... So it fluctuates from 4-14mph off, at a given speed.

I haven't taken any hard data with my GPS ticker compared to my odometer. But ive noticed it ticking off miles just before i get to the mile marker.

[Fleetw00d]

At 20mph my GPS reads at 26. At 35 its dead on with my GPS. And when my GPS says 55MPH my speedo reads 69mph... So it fluctuates from 4-14mph off, at a given speed.

Are those values consistent (is 20 on the speedo always 26 on the GPS)? If you use cruise control, will it hold a steady speed?

Does your GPS function also show distance? To check the odometer, check the distance vs. time. Try driving 55 according to the GPS, in one minute your odometer should increase by a little over 0.9 miles. If it increases by about 1.15, then the odometer is following the indicated 69 MPH. If the speedo and odo are both this erratic, the VSS is probably a good bet. You might want to check the connector to make sure it is tight and clean before replacing the sensor.

[bcjammerx]

mines off by 3%, except at 50...spot on

[islandhopper]

Are those values consistent (is 20 on the speedo always 26 on the GPS)? Can you tell if the odometer is working correctly? If you use cruise control, will it hold a steady speed?

Yes, those number are consistent. When i don't have my GPS i go by those numbers as to avoid getting a ticket and they hold true once i have the GPS again.

Both my odometer and trip meter tick away fine, im just not sure if they are ticking away the correct increments. And i don't have cruise-control, i have a DX coupe.

[Fleetw00d]

Added some to my previous post, apparently after you read it.

To check the odometer, check the distance vs. time. Try driving 55 according to the GPS, in one minute your odometer should increase by a little over 0.9 miles. If it increases by about 1.15, then the odometer is following the indicated 69 MPH. If you drive 60 according to the GPS, highway mile markers should be exactly 60 seconds apart. If the speedo and odo are both this erratic, the VSS is probably a good bet. You might want to check the connector to make sure it is tight and clean before replacing the sensor.

[islandhopper]

Added some to my previous post, apparently after you read it.

To check the odometer, check the distance vs. time. Try driving 55 according to the GPS, in one minute your odometer should increase by a little over 0.9 miles. If it increases by about 1.15, then the odometer is following the indicated 69 MPH. If the speedo and odo are both this erratic, the VSS is probably a good bet. You might want to check the connector to make sure it is tight and clean before replacing the sensor.

Yup, i saw that. Thanks for the help. I will be thoroughly checking my odometer against my GPS tomorrow on my 30mile drive to work. I've been trouble shooting this problem for a while now and with your suggestions i should be able to make a concrete decision as whether to change out the VSS or not.

Thanks again.

[92exa6]

My 90, 93 wagon and 93 sedan all read within 1 mph of the GPS speed. 93 EX actual speed is about 2 mph low at 60. 99 E350 actual speed is about 1 mph high at 60. A 4 mph error would drive me crazy (I'm an engineer).

I remember driving when the only people with GPS were in the military, and I still don't use it, so I guess that's why I could care less if my speedo is spot on. Both my car and my bike show a couple mph high on those roadside radar trailers at 25.

I know the Speedo Healer is out there to for digital speedo equipt motorcycles to correct for gearing/tire size/normal tolerance/etc., is there something similar for cars?