09 speedo showing incorrect?

I have the 09 Taco 4x4 and have noticed an error in the odometer. I took it out to the kilometer (canadian, eh) test range out of town and found it reported plus 250 to 300 meters over 5 kilometers (klms). Thats 273 - 328 yards over 3.1 miles. Which translates into 60 Klms over 1000 klms (37 miles over 621 miles), 600 over 10000 klms (327 miles over 6214 miles) and so on. This is a pretty big error! This effects my warranty, which will cause mine to expire prematurely.

I had to take the truck in for something else and asked that they (another closer dealership) check it out for me. This is a laugh, the sevice guy told me they tested it against another Taco and found that they were both the same and therefore correct. Laughing I said "that this only proves they're the same, NOT correct" and "only an idiot couldn't see the difference"....well I guess you can see where this went! Perhaps not the best thing to say but it's "true".

I wrote Toyota and outlined the problem and they said they'd get back to me...that was 3 weeks ago...I'll not hold my breath! I took it back to where I bought it and talked to their mechanic and he said he was unaware of any problems with 09 Taco's relating to my findings. I asked what was required to fix it and he said something about gears that had to be changed or altered but had no real solution. We left it at that for the time being.

Since then I've done some research on the web. Using my tires 245/75R16 and simple math I discovered that the odometer has to revolve around 433 times per kilometer to get the error I'm seeing. Therefore if I use a 235/70R16 tire and times by 433 it equals 1 kilometer almost exactly. See: I guess that this would make my speedo incorrect too. I never knew that small changes in tire sizes would have this much effect!

If my logic is fuzzy I apologize, tires, speedos and odometers (Oh my!) are not my thing. But if I'm right should I exchange my stock tires for 235/70R16's, or should I wait to see what Toyota has to say...again not holding my breath!

Personally I think Toyota should fix this problem or spring for new tires that correct the problem that they created in the first place!

 

My new SR5 measures about 3-4 mph high.

 

I've worked for GM dealers for the last 19 years, and in the early nineties when we replaced the speedo in police cars, they were different. They were calibrated for accuracy, because the stock speedos were off by a few mph. You would think that modern cars with electronic speed sensors would be more accurate, but there will always be variables when it comes to speed.

 

2~3 MPH is all?

Once the tires wear down it will change 2~3 mph. This is pretty normal with cars I've had, and better than most.

 

Hmmmmm... I'm not so sure that it's just the speedometer. The speedometer on my '09 appears to be about 3 mph fast with my buddy's scangauge hooked up. The odometer is reading 6.2 miles when I've only gone 6 based on mile markers on a relatively straight section of highway. I'll have to find someone with a GPS to test it out, because the error I'm getting would be adding about 12 miles every tank of gas (assuming I get a reading of 350). I'm most interested in getting accurate MPG readings.

 

Ummm...no you're losing 1200 miles from your warranty. If your odometer is reporting more milage than is actually being driven then you'll hit your warranty limit sooner than you should! In other words your being ripped off!

 

uh yeah... that's what I meant

 

my 05 Taco reads about 2mph faster than my nuvi.

 

im having the same problem....ive had the truck 2 weeks and took it up to the dealership yesterday and they handed me a paper with the acceptable differences...thats a bunch of bull...i took it to a shop and had it dyno tested and it came back as being .3mph difference higher than what is acceptable by toyota...im really upset about this..i live 7miles from work and i already have over 1000miles on this thing...the service manager is supose to call me monday so i will be back tomorrow if anyone wants to know whats going on