gps says 55mph speedometer says 60mph?

my head hurts....

 

Well sure when you say it like that it makes sense! Thanks for the correction!

 

those stealership mofo''s. since my speedo says im going 5mph faster then that means im racking up miles faster. im gonna have to get them to fix that.

 

They may and probably will tell you it's within Toyota's specs so there is no need for them to fix it.

 

I just noticed my GPS reads about 5 kms/hour (3mph) slower than my speedometer too. Im sure that there is some degree of difference with all car makes out there. My Girl friends VW Golf is almost dead on though when I checked it with the GPS. Anyone ever try comparing the accuracy of other vehicles?

 

I don't want to admit it, but my GMC Sierra was dead on (+-.5mph) with the stock tires. When I had 34 inch tires installed, i simply changed the tire size setting with my hypertec controller. After this the truck was still every bit as accurate.

 

Either way you gotta hit 88 mph before the flux capacitor kicks in?

 

My speedometer is app 3 mph faster than GPS in the 65-80 mph range.

 

My 2007 read 4mph over actual (GPS) speed @ 60mph.

Swapped out the worn OEM 215R70's for 235R70's and it corrected to just right (GPS=speedo) at 60mph.

 

I got the same 55/60 reading on my 09. The dealer confirmed that the speedo was off by about 10%, but he also said the computer indicated fewer miles than the odometer reading, meaning the sensor was correct, but the speedo was not. (I guess the computer keeps track of miles nowadays?) They said, "never seen that before." I've been waiting three weeks for them to contact me because they said the Toyota service rep. had to look at it, and they would probably have to send the truck out to a speedo shop to have it calibrated. My 99 Taco's speedo was right on with the stock tires. I guess that's progress, Toyota style.

 

my gps says 100 km and the speedometer says 97 km with lt265 70 r17 tires. put new tires on lt265 75 r17 and it is dead on now

 

This has been a fun thread. Forget the math and just think a minute. A larger tire travels farther every time it makes one complete rotation, right? If you don't agree, then try this: Take a wheelbarrow tire and a tractor tire. Stand them side-by-side and push each of them one complete rotation. Which one traveled the farthest (the tractor tire)?

So, if you have great big 38" tires on your Tacoma and no gadget to correct your speedometer (your odometer is run by the same mechanism as your speedo) and your speedometer is set at the factory for a 29" tall tire, then you can reasonably determine that your pickup will have traveled farther every time the tire makes a complete revolution than the odometer thinks it has. Ergo, GPS says 100 miles, odo says 92 miles (just so we all understand, GPS doesn't care what size your tires are).

Also, some manufacturers' speedos are factory set to read a little fast, so people don't complain about getting stopped for speeding all the time. Incidentally, many states also set their radar equipment to allow a couple miles per hour fudge factor to the benefit of the citizen (ie, actual speed is 65 and the radar reads 63. Again, GPS doesn't care. It only reads the relationship between the satellites and the GPS unit. It doesn't care whether it is in a car, airplane, or bicycle, or in the hand of a hiker. No fudge factor built in.

Additionally, if you have the above 38" tires on your vehicle, and you start figuring out your gas mileage according to your odometer mileage, you are going to get very depressed. Your mileage will appear to have dropped off the scale on the low side, while in reality it is not so bad. Try figuring your mileage by using GPS distance traveled rather than your odometer. You'll be much happier.

Now about the warranty thing. I had never thought of that! Getting bigger tires is looking better all the time!