Guys, I have a stock DX, stock size tires and I assume original tranny. I replace the stock cluster with one that has a tach and some gauges. Everything seemed to working fine until I noticed a 5 mph difference between the gauge and my GPS unit at most all speeds. The local auto shop said it listed two different vss sensors, so I assume, the difference would be in the number of pulses produced.

I pulled out an assortment of stock vss sensors, thinking I must have one from a LX or EX and that would cure the problem, but , ALL of ones I had also were 5 mph off.........what am I overlooking.......thanks......

 

people can change clusters around all day, even to jdm ones, and will read the original vss

install the original cluster and if it corrects the issue, you know where the problem is

 

I have a Navigon in my 00' Si and it does the same thing, but it's off by 2 mph. no matter if i run the stock 195's or my current 205's

Same goes for my 03' Evo that i got a Magellen but i do run 255's on there.

I believe the best way to go as far as GPS systems is the Garmin or a Tomtom.

 

I've always heard it was fairly normal for most production cars to be off on the speedometer. I think they're usually a little slow.

https://honda-tech.com/forums/showpo...63&postcount=6

 

Mines off a few mph as well, same reading two different clusters, stock tires, its off slower than actual so it probably keeps me from getting speeding tickets.

 

I have a Garman and just assumed it would be fairly accurate. Would have no clue as to how to check a GPS unit. I could understand a few mph off , but five is too much. I can understand how the analog parts on the cluster could slow down due to wear, heat , friction,ect, but , was wondering if there are any differences in the drive or driven gears that spin the vss. Any differences in outputs for manual or automatic trannys?

I have a few other clusters, including the stock one, and will swap them in and see what the results are. thanks for the opinions.....

 

It's a well known Civic speedometer issue. When I connect my scan tool that reads live data, the mph on my speedometer is about 3 mph faster than what I read from the scan tool, which is showing the correct speed (same as GPS). Therefore, the problem is the speedometer not the VSS.

 

Just a quick question.. I thought because of the speed sensor being in the tranny that you can run any size tires and it wont mess with the speedometer reading. I noticed a couple people say that they run different size tires and i figured that you can run different size tires as i want slightly smaller ones to gain acceleration.. I do not have a gps in my car so i do not know if the speed is already off any.

 

no biggie people never do the exact speed limit anyways, my gps is off from my speedo but meh!

 

Due to the fact that the wheels are directly attached to the tranny via the axles, the rate that the wheels/tires turn is directly proportional to that of the gears in the transmission. If you change the tires so they are rotating faster, the gear will rotate faster, the engine speed will be affected, the speedometer reading will be affected. I hope that makes sense.

To the O.P., every Honda I've ever driven has this "issue." My Civic reads about 4 MPH fast at 75-80, my parent's have an Odyssey that reads 2-3 over at highway speed, I think it's just how they're made. Better than it saying you're going slower than you actually are.

 

Both my EG and EK are inaccurate. I believe the VSS itself
is the reason. Using a GPS:

31 mph on the speedo gauge is actually 30 mph
42 mph on the speedo gauge is actually 40 mph
53 mph on the speedo gauge is actually 50 mph
64 mph on the speedo gauge is actually 60 mph
75 mph on the speedo gauge is actually 70 mph

I put on 195 60 14s and it helped a little.

 

What's the basis for this belief?

 

I could be wrong. I saw a thread about a device that "fixes" the signal from the VSS, making the speedo more accurate.

 

Sorry, I missed this post.

 

I agree with Ronj@ht. Mine is off, both my ex cluster,dx and my freinds SI cluster.

I am sure my wheels have a little to do with it, but it doesn't bug me one bit.

 

mine goes by the same exact chart (94 ex auto cluster) that mcvtec provided

 

mines always 5 miles faster so now i just drive in kmph lol

 

This is true.

My scangauge and my GPS both read 3-5 mph faster than the speedometer, depending on how fast I'm going. The faster I'm going, the more it's off. It tends to read about 2 mph high at 35mph, 3mph high at 60 mph, 5 mph high at 70mph.

The interesting thing is that the scangauge reads the speed directly off of the speedsensor, and the scangauge always reports the same speed as the GPS. So, the VSS is reading the correct speed, but the speedometer always reads a bit high. It's because of how the dial is calibrated. In fact, in newer Audis, they've corrected this problem by recalibrating the numbers on the dial so that they get closer together as the dial goes up.

I've noticed that this affects my Civic, my CRV, and my Accord. It's a Honda thing. Enjoy the tickets that you won't get because you're always thinking that you're going faster than you really are.

 

Ok, seems it is fairly common that a lot of speedos are off. Now, is the odometer in sequence with the speedometer, meaning it is also inaccurate . So what ever miliage you think you are getting is incorrect also..........hmmmmmnnnnnn. If the offness varies with speed, that would be difficult in figuring how many tenths per mile to subtract in order to find how many miles per gallon one gets with a tank of fuel. Seems I may have to retract some boasting abbot the little cars MPG.

I guess it would take something like an in line device that would allow for adjusting the pluse rate going to the speedometer from the vss to get things accurate , anybody ever heard of something like that.

 

I believe the speedometer and odometer are independent of one another, and I have never heard that the odometer or tripmeter suffers from the same inaccuracy as the speedometer.

 

cause civics are cool like that and stop worrying about it

 

i've seen that, too. and it's not just on audis. i guess that's the simplest way of correcting the issue. i think it actually looks cool. seems like you're going faster than you really are when the needle is closer to triple digits.

 

My speedometer reads about 2-3% higher than my VSS, but my VSS reads another 3-4% higher than my GPS. That would inherently create odometer error.

I'm using my OEM cluster, wheels, transmission, and tire size.

 

Speaking of tire size, let's talk about a 195/55-15, which is a common size for 96-00 Civics. New, the tire should be 23.44" in diameter, assuming it was actually made exactly to the stated size. Tires generally come with 10/32" of tread depth, and are illegal for road use after they wear to 2/32". This results in a diameter change of 16/32" ((10-2)*2), or 1/2", over the life of the tire.

1/2" is 2% of the diameter. When should the speedometer and odometer be accurate? How much variance in diameter between different brands is tolerated? Factoring in that the rolling diameter of a tire changes with speed, and the amount it changes depends on the tire construction and thus varies from tire to tire, how accurate do you really expect the speedometer to be?

I have a set of 205/45-16 tires on 16x7 wheels that are both wider and larger in diameter than a different set of 215/45-16 tires also on 16x7 wheels, when the 215s should be wider and taller... Close enough for me, but certainly not accurate to the size they claim to be.

 

^^ These are very good points, and this is why you can only be so accurate by determining vehicle speed from axle speed. That's why I just use my GPS.