Around my neighborhood we have speed limit signs with radar guns built into them. They tell you how fast you are going along with the actual speed limit.
The speed indicated on these devices is consistently 4-5 miles per hour lower than what my speedometer shows.
I know that most car speedometers show miles per hour a couple miles below actual, but 4-5 miles per hour seems too much.
Re: Speedometer 4-5 miles per hour under actual speed
You're so on this. On each of four 200 mile trips the odometer was off, 1 mile under the actual distance on each trip by the mileage posts. But the indicated miles per hour was 5 to 7 miles per hour faster than actual by the car computer, radar checks and hand calculation. That's 7 to 8% error. I do overinflated my tires to 40lbs., but that should make the miles per hour error smaller and explain the under odometer reading. What gives here? Does anyone have an answer?
Re: Speedometer 4-5 miles per hour under actual speed
Quote:
Originally Posted by wallpad
Around my neighborhood we have speed limit signs with radar guns built into them. They tell you how fast you are going along with the actual speed limit.
The speed indicated on these devices is consistently 4-5 miles per hour lower than what my speedometer shows.
I know that most car speedometers show miles per hour a couple miles below actual, but 4-5 miles per hour seems too much.
Is anyone else's TCH speedometer this far off?
Paul
The inaccuracy of the TCH speedometer has been the subject of significant discussion since June when I first pointed this out. A number of forum members have tested their speedos with handheld GPS devices and have verified this. You can search these various threads for more on this topic.
Re: Speedometer 4-5 miles per hour under actual speed
Quote:
Originally Posted by freeagn
I do overinflated my tires to 40lbs., but that should make the miles per hour error smaller and explain the under odometer reading.
Does the tread stretch when you over-inflate? I think not! The sidewalls stand taller, but the circumference of the tread, held in check by steel belts remains virtually unchanged. If the tire circumference is the same at different inflation pressures, then the speedometer/odometer reading will also remain unaffected by inflation changes. The car will ride higher at higher pressure, but the tread with the steel belts do not stretch, and the tires will still turn around exactly the same number of times per mile as before.
Re: Speedometer 4-5 miles per hour under actual speed
I searched the threads and found the ones about the speedometer being off. However, other folks seem to see a 5% difference between actual spp=eed and speedometer. I see a 10% difference. If my speedometer shows 40, I am actually going 36. If my speedometer shows 50, I am really going 45.
I'm fine with a 5% difference, but it bugs me that it's 10%.
Re: Speedometer 4-5 miles per hour under actual speed
On the bright side, it just might get you out of a reckless driving ticket when you're doing 90 on the interstate!
Seriously, I think any discrepancy greater than 5% should be grounds for a warrantable repair. Contact your dealer, and be sure to post back and let us know what happens. Thanks.
Re: Speedometer 4-5 miles per hour under actual speed
The Toyota Camry Hybrid Repair Manual (page ME-40) gives the factory specifications for the speedometer as follows:
Reference: miles per hour (for USA)
Actual speed 20 — Acceptable range 20.0-23.0
Actual speed 40 — Acceptable range 40.0-43.5
Actual speed 60 — Acceptable range 60.0-64.0
Actual speed 80 — Acceptable range 80.0-84.5
Actual speed 100 — Acceptable range 100.0-105.0
Actual speed 120 — Acceptable range 120.0-125.5
Reference: km/h (for Canada)
Actual speed 20 — Acceptable range (17.5-21.5)
Actual speed 40 — Acceptable range 38.0-42.0
Actual speed 60 — Acceptable range 58.0-63.0
Actual speed 80 — Acceptable range 78.0-84.0
Actual speed 100 — Acceptable range 98.5-104.5
Actual speed 120 — Acceptable range 119.0-125.0
Actual speed 140 — Acceptable range 139.0-146.0
Actual speed 160 — Acceptable range 159.0-167.0
Actual speed 180 — Acceptable range 179.0-188.0
Actual speed 200 — Acceptable range 199.0-209.0
Actual speed 220 — Acceptable range 219.0-230.0
You'll note that the speedometer is not allowed to under-read, as per international legislation. The error is supposed to be less than or equal to 5% according to Toyota's specifications. Mine seems to be accurate to within 1-2%.
I have not yet been on the freeway with the Garmin in in the car. BTW - it was registering 7 satellites most of the time.
So - it would appear that our fuel economy figures would be inflated as well.
When I buy my new 17 or 18 inch wheels for summer, I will run a slightly larger (diameter) tire to help make up for the error.
Regards - Randy
If there's one thing I've learned in online forums its this: Never argue with an idiot, they'll drag you down to their level and beat you with experience!
Speedometer 4-5 miles per hour under actual speed
Re: Speedometer 4-5 miles per hour under actual speed
