2007 Toyota Tacoma odometer

You need to go up the food chain with that problem.

I would really have a go at them. While the markers at the side of the road are not the most accurate, they should be within a few hundred meters of where they should be. In Australia our design rules allow for a 5% variation (not the 40% you get) due to the problems with mass construction, but this should be only limited to cars that have a cable speedo. I don't know what the rules are like in the US but it would be classed here as not functioning correctly and would have to be fixed, either by the maker or you.

Be warned though, just because the odometer is out does not mean the speedo is out, whith larger diameter tyres you could now be going faster than you think.

Also seeing as the dealer has put you off, call Toyota head office directly and ask to speak to a regional manager or the managing director. The warrenty is with them directly not the dealer so go straight to the source. If you are polite and don't sound too pissed they will usually be extremly helpfull.

NicK

You will get a toyota fix if you persist. But I'm sure you'll like the larger tires of the prerunner and 4wd

Maybe the dealers switched the original tires from the truck you eventually bought with another truck before you bought it to satisfy another Customer. (I've seen dealers do this- nothing sinister, just the dealer switching tires/wheels between vehicles they "own"). Do you by any chance have the original window sticker? It should list the size of the tires installed on your truck at the factory. It would be worth checking this against the size tires actually on the truck when it was delivered to you.

A 38% error is completely ridiculous. I am surprised you could fix the error merely with tires. I am even more surprised that a Toyota dealership would claim that this ridiculous level of error was acceptable. I can't remember the last new car I bout where the odometer was more than a little off (i.e., read significantly more or less miles than I actually traveled). I checked by last 5 new vehicles against both Interstate Mile Marker and GPS navigation systems and 4 of the 5 (all Fords) had odometers that were 1 % to

3% pessimistic (i.e., the odometer says I drove 97 miles, when I actually drove 100 miles). The other, a Saturn, had an odometer that was about 3% optimistic (100 actual miles = 103 indicated miles).

As far as I can tell, there are no Federal Regulations that specify an acceptable accuracy for an odometer. This seems strange, since there are regulations that make odometer tampering a crime. It seems like it is OK to equip a car with an odometer that is wildly inaccurate, but illegal to change the inaccurate reading.

Ed

The particular problem of the dealer not fixing problems and declaring them normal? Yes!

SPEEDOMETER and ODOMETER readings are completely different things. A speedo that reads in error of 4 mph is a much different thaing than an odometer that reads wrong by 4 miles in 10.

I do not agree. The markers should be within a few meters of where they say they are. My disagreement ias solely your assertion of the rate of error that the highway department will tolerate. I think that the error in placing a mile marker is within a few meters, not a hundred meters. A highway marker will be omitted before it will be placed in the wrong location.

If a marker says it is 27.5 miles from somewhere, you can bet that it is within 10 meters of where it is supposed to be. Keep in mind, the mile markers are not measuring straight line miles, they are measuring highway miles, so a highway that twists and turns can place you ten miles form the start point as the straight line goes, but over twenty miles as the highway goes.

This is true. The larger tires will make the Speedometer read slow, so a displayed speed of 60 might be an actual speed of 65 or more.

In the city they maybe but out in the country where I live you sometimes can't be that accurate. Our roads go over very changeable soil types. In the black soil plains the main highway has more waves in it than a rollercoaster. Personally I don't trust them to perfectly accurate with the distance markers over our distances. I think 200Km +- 100m is fine. when the raod is dead straight and you don't see another car for the whole distance I don't really care.

I don't live in the city either. I do live in California, and your mileage may vary, but they will not plant a mile marker before they plant one in the wrong place.

The purpose of a mile marker isn't for you to calibrate your odometer or speedometer (but they are useful for that), they are for emergency crews and highway maintenance crews. When you are on the highway and observe a crash, you can tell the emergency operator that you are east of mile marker 27.5, and they have a better idea of where to send the response crew. Cellphones these days have a GPS-like circuit built in that helps the emergency operator find you as you are making the call, so your observance of mile markers isn't all that important, but that is why the markers are there.

If there is a mile marker planted on the side of the road, you can take it to the bank that it is precisely where it says it is, within a few meters.

I found this research paper:

and while I did not read all 108 pages or some other info on other sites, I found some surprising information. I would have thought that there is a uniform method of placing mile markers, but there is not, and methods and accuracy vary by state.

Among the methods used to measure position are optical survey instruments, laser distance measuring, measuring wheels, digitized aerial photographs, and distance measuring devices installed in vehicles (fancy odometers), with the most common being a combination of several methods.

Some are measured in 2 dimensions and some are measured in 3, taking elevation into account.

Some measure from a lane centerline, some measure the centerline between directions, and some measure between markers.

There is relative accuracy (accuracy between markers and geographic locations) and there is spatial accuracy - distance from a specified starting point in the road system.

Depending on the state and the method used to place the particular marker, it looks like accuracy will vary from inches to about 300 feet.

For the purposes of determining odometer and/or speedometer accuracy, the most accurate method seems to be GPS or measuring the mile marker distance over as long a distance as possible and averaging out.

Your mile markers are used for different things. Ours are only used to tell you the distance to the next town along the road and are usually every 20 to

30 kilometers so if it's out by 200m it doesn't really matter. In the country at best you can only give a rough area where you are anyway and thats usually enough.

By the way (I'm not being picky) our mobiles dont cover much for real emergancy use. My state along covers some 720,000 square miles (I think it's about 10% bigger than Texas with about a fifth the population) and less than

10% is covered by mobile reception.

they are. My disagreement ias solely your assertion

that the error in placing a mile marker is within a few

will be placed in the wrong location.

can't be that accurate. Our roads go over very

waves in it than a rollercoaster. Personally I don't

distances. I think 200Km +- 100m is fine. when the raod is

really care.

may vary, but they will not plant a mile marker before

speedometer (but they are useful for that), they are for

and observe a crash, you can tell the emergency

of where to send the response crew. Cellphones these

you as you are making the call, so your observance

the bank that it is precisely where it says it is,

and while I did notread all 108 pages

would have thought that there is a uniform method of

laser distance measuring, measuring wheels, digitized

(fancy odometers), with the most common being a

into account.

directions, and some measure between markers.

and there is spatial accuracy - distance from a

looks like accuracy will vary from inches to about

accurate method seems to be GPS or measuring the

I would imagine the distance traveled would very quite a bit even between a cars left and right side tires.

Dan

And for the front and rear wheels

I would imagine the distance traveled would very quite a bit even between a cars left and right side tires.

Yup, the distance traveled varies enough to require a differential ;-)

We're not talking about the "Distance to next town" signs meant for use by the motorists. Look for smaller markers placed by the road maintenance crews at every bridge and improvement. I'll bet you the Australian highways have them, but you never had a reason to notice.

They are used to catalog all the drain culverts, bridges, tunnels, etc. so they can go clean out the right one. And keep records of the ones that need work. When they repair the pavement the contractor gets paid by the mile/KM, so it's important that they can survey what they did.

Ours are marked in miles to the hundredth from the staring point of the highway down the center-line, and they're accurate to the rounding factor. (.01 mile is 52.8 feet or 16 meters and change.) Close enough to find the right bridge...

For example the marker for a drain culvert undercrossing might be signed as (Mile) 23.96 (which could be give or take 50 feet) and a bit farther on you'd see a standalone sign for (Mile) 24.00 which will be spot-on.

That's not a problem if you have a vast flat area with the occasional outcropping (Ayers Rock?) that you can put a base station on top of. They are getting really good at disguising the base station antennas as native trees - I've seen them done up as various species of pines, oaks, elms, date palms, queen palms, saguaro cactus... It's all in breaking up the silhouette and getting the color match close to the real trees surrounding it.

Or you put up a 40M tower for the antennas every 50 or 100Km down the highway, in the outback that'll give plenty of coverage with only a few towers. The equipment has been miniaturized to where it can be a single rack cabinet at the base of the tower. If they aren't heavily used, solar cells and batteries will run them.

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I'm not talking about the signs that say, 28 miles to Somewhere, 15 miles to Somewhere, 7 miles to Somewhere, Somewhere, Next right. Those signs are all over the map for accurate placement.

We have small signs, typically about 9 inches x 27 inches, or something like that, that are white with black letters (numerals in this instance) that notate the miles, typically in half-mile increments, along our federal (interstate) highway system. Our State Highways also have these markers, but the state highways are more likely to have signs missing. Our signs mark the miles upward as one travels northbound and east bound, and count downwards as one travels southbound and westbound.

Zero is at the county line, or the beginning of the highway if the highway starts at an intersection other than a county line.