On board computer MPH read-out

[gizmopt2002]

Noticed something odd on Thursday. I was on my way back home from Milwaukee (About a 1h 30m drive), and since I saw at least 8 troopers pull people over in the first 15m back, I decided to keep it at 70 Cruise Controlled, this of course meant that I was actually going 68, 3 MPH over the limit, I decided to reset both the MPG and MPH, and a little while into listening to my friend watch American Pie 5 The Naked Mile ( I know lol) I looked down and noticed that the AVG. MPH was...68. I found that odd since I figured it was set ahead just like the ODO. BTW, the AVG. MPG read 22.5 the whole way, probably more like 20ish then. Just an FYI randomness.

 

[Falls]

I've done similar tests on my 4R since so many people said they were so inaccurate . I went on a flat stretch of road on a calm day , set my cruise at 55 and then reset my comp and cruised for about an hour , comp read 55 the complete time.

I also did a gas milage check and found it to be very close to my milage check with gallons used and miles traveled.

I don't know why everyone says they aren't worth a crap . Mine works fine.

 

[ProMed]

When your speedo (and apparently the computer) says 55 you are actually going a little slower. However, I am not sure what percentage the factory speedo error is on the T4R.

 

[dingo]

When your speedo (and apparently the computer) says 55 you are actually going a little slower. However, I am not sure what percentage the factory speedo error is on the T4R.

I do notice a slight discrepancy in the speedo's needle position vs. say what my Garmin says. The gps always posts a slightly (about 1.5 mph) slower speed. By contrast, when I drive by those radar/speed sign trailers which tell you how fast you are going, they always post a slightly higher number (go figure).

 

[<<<<]

I wish there was a way to calibrate the darn thing. Mine is always reading 20 MPG while I'm actually getting 16 to 17 MPG. Therefore, I never use the thing, instead I have a range displayed, which seem to be somewhat accurate.

 

[toto]

The speedo on my 4Runner is the first one I've ever had that's accurate, as confirmed with a Garmin StreetPilot.

My other cars have read high, usually by about 5%. That's 3 MPH too high at 60 MPH.

 

[gizmopt2002]

Actually I'm pretty sure the speedo is 2 MPH too high.

 

[keylay31]

Actually I'm pretty sure the speedo is 2 MPH too high.

Now why the hell would they do this? :bash:

Yes, I can think of the reasons, but FRICK! I want to know how fast im going.


Quick thought, does this mean that when my odo reads 100k, I've actually gone like 12,857k?

 

[gizmopt2002]

Actually i think the ODO might be a little off. I set up a trip exactly ten miles, but the ODO read a little higher. Not sure, I'll have to do it again.

 

[gizmopt2002]

I'm pretty sure that if you reset it on your next fill-up, and go on a highway for however many miles, the MPG will be pretty damn accurate. However, if your in frequent s & g traffic, it will be off.

 

[SciRunner]

The speedo is freakishly accurate as confirmed by my Garmin Nuvi 350. I haven't confirmed the ODO yet.

 

[wazzuFreddo]

You should try sportbikes. The spedo on my Suzuki has to be at least 6-7 MPH off.

 

[bpwwer]

I had an Integra that came from the factory with the speedo and odo 10% off (read high). And I use to wonder why I cops never gave me a second look when I was 10MPH or more over the posted limit

When I started doing TSD rallys I had it calibrated. That involved adding a gear box in-line with the speedometer cable. After that it was within 0.1%

 

[Koz]

On motorcycles, the speedo is about 10% faster then your actual speed. It also varies depending on your speed, as you go faster the error percentage gets greater. As of 2001 the motorcycle manufactures have agreed to limiting the top speed to 186mph (on all motorcycles). I have the last model (2000) with the 230mph speedo.

Koz

 

[ProMed]

Now why the hell would they do this? :bash:

Yes, I can think of the reasons, but FRICK! I want to know how fast im going.


Quick thought, does this mean that when my odo reads 100k, I've actually gone like 12,857k?

Almost every car sold has a factory speedo error and I would be amazed if my 4Runner's speedo was perfect from the factory. I remember someone posting on here the percentage for the 4th gens, but I can't recall the exact figure, it was something around 2-4%. However the odometer has some sort of federal law that they must be accurate from the factory.

 

[Jacobzky]

When your speedo (and apparently the computer) says 55 you are actually going a little slower. However, I am not sure what percentage the factory speedo error is on the T4R.

my speedometer reading is exactly the same reading on my Magellan nav/gps. did this experiment on a long stretch of freeway and set cruise to 70 mph on the needle, and is gps is on the spot right.

like some, not all odometer is accurate.

 

[Falls]

Nothing is perfect !!

Mine works fine but I really have no reason to use it so I keep it turned off.

 

[ProMed]

my speedometer reading is exactly the same reading on my Magellan nav/gps. did this experiment on a long stretch of freeway and set cruise to 70 mph on the needle, and is gps is on the spot right.

like some, not all odometer is accurate.

Do you have one size larger tires?