Speedometer not accurate

[Sagebrush]

A GPS app on your phone is only accurate for straight stretches. I've checked mine, and I'm within 1 MPH.

Close enough.

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[Daveintb]

After I swapped out my tires to 33”, I took it to the dealer to have the speedometer programmed as I wanted an accurate speedo. After checking with his techs the service manager told me that they have no way of doing that. . Guess I’m just stuck with a 3-4 off speedo.

 

[ambit]

My SR5 is low by 2-3 mph at "80" and the gas milage remaining lies too.

 

[tacorancher]

I put 275/70/18s which are almost an inch taller and my speed still shows I’m 1-2pm mph slower than GPS lol…. Guess I need to go even bigger.

I drove 150+ miles today at 65-75 mph and it was off 2mph most of the way (showing 2mph slower than actual)

 

[BLtheP]

I can see being conservative on the speedo but 2 mph is too much. Doing the math, at 30k indicated the true mileage is 31k. At 75k indicated it's 77.5k.

Typically the odometer is accurate while the speedo is fast.

And if it wasn’t correct on the odometer, then your math would be backwards. You’d show 31K on the dash when you actually had only gone 30K. But the odometer can’t be inaccurate like that because they can’t short people on warranties.

So just drive it and know that when you’re going highway speed, you’re actually traveling 3ish mph slower than the dash says.

 

[sprocket47]

My TRD Sport Speedometer shows 2 MPH slow at freeway speeds according to my GPS. Stock tire size. Am I the only one?

I had a 2021 Sequoia and the speedometer was also off (stock tires), just like like my new Tacoma. I just set the cruise to 1-2 mph high and it's all good.

 

[tacorancher]

Typically the odometer is accurate while the speedo is fast.

And if it wasn’t correct on the odometer, then your math would be backwards. You’d show 31K on the dash when you actually had only gone 30K. But the odometer can’t be inaccurate like that because they can’t short people on warranties.

So just drive it and know that when you’re going highway speed, you’re actually traveling 3ish mph slower than the dash says.

Curious how the odo stays accurate? People with 35s would be getting a better warranty otherwise

 

[TheBandit]

Neither the speedo or odometer is really completely accurate in my experience with the SR. I got my truck on 245 70 r17's but since it's the manual and I get the more powerful engine, I put on 255 80r17s.

Something I noticed pretty quickly owning the truck on a road trip with other people was that the 245's read about 3mph faster on the speedo at highway speeds than any of the other cars I was around. I tested this against the local speed warning things, and it was always reading higher on the speedo by a fairly considerable amount.

The difference between the 30.5" tires and the 33" tires is night and day. The manual transmission is clearly geared for the larger tires-less lurchy- and I found that the speedometer is pretty much dead accurate on the 33s through the same methods I tested the smaller tires.

I got bored on a road trip along i70 though testing the mile markers against my odometer with the 33s and found that for every 2 miles I went, I had to go 21 1/10 mile markers. Or just about 1.05x the odometer reading. I compared this to distance between gas stations vs what my trip odometer read and damn it, it was that 5% difference.

Basically the SR at least is geared and speedometer accurate on 33s but the odometer reads about 5% under what the actual distance traveled was

 

[tacorancher]

Neither the speedo or odometer is really completely accurate in my experience with the SR. I got my truck on 245 70 r17's but since it's the manual and I get the more powerful engine, I put on 255 80r17s.

Something I noticed pretty quickly owning the truck on a road trip with other people was that the 245's read about 3mph faster on the speedo at highway speeds than any of the other cars I was around. I tested this against the local speed warning things, and it was always reading higher on the speedo by a fairly considerable amount.

The difference between the 30.5" tires and the 33" tires is night and day. The manual transmission is clearly geared for the larger tires-less lurchy- and I found that the speedometer is pretty much dead accurate on the 33s through the same methods I tested the smaller tires.

I got bored on a road trip along i70 though testing the mile markers against my odometer with the 33s and found that for every 2 miles I went, I had to go 21 1/10 mile markers. Or just about 1.05x the odometer reading. I compared this to distance between gas stations vs what my trip odometer read and damn it, it was that 5% difference.

Basically the SR at least is geared and speedometer accurate on 33s but the odometer reads about 5% under what the actual distance traveled was

Agree that 33” is ideal for gearing. 34-35 also would work fine. Toyota did a great job on this power train.

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