2018 Outlander PHEV speedometer inacuate?

[elm70]

Actually Andrev has a point here

I understand that in the past it was not possible to have high accuracy on the speedometer, and due to law/regulations car manufacture have been forced to add en error and show always speed above the real one.

But now, every car has GPS on board, and GPS is quite accurate on reading the real speed ... and the car could be tuned in real time to always show the real car speed (even inside a tunnel without GPS signal)

I think ... car manufacture got used to show speed in excess .. and possibly also driver got used to drive a bit faster since they know that the speedometer show an overestimated speed ...

But maybe it would be wise to change the law and regulations .. and force car manufactures to provide accurate with an error below 1% (as well ... countries should not punish people for have speed up to 1% above the speed limit ... I know most wise country and policeman do already ... but not everywhere and not every police man)

 

[anko]

Actually Andrev has a point here

He does not, as his point was:

We are living in a world of high technology and seeing a car manufacturer unable to give you the exact speed you are driving is frustrating and make me questioning all other informations the software system is expelling!

We have tried to explain to him that the manufacturer is very well able to show close to actual speed (check OBD data) but chooses not to do so (because the law does not allow him to do so in some parts of the world). For sure, it says nothing about the other information provided by the dashboard.

https://www.theglobeandmail.com/globe-drive/culture/commuting/why-you-may-not-be-driving-as-fast-as-you-think/article11487709/:

"Speedometers are designed to never show speeds lower than actual speed." Thomas Tetzlaff, Volkswagen Canada's media relations manager, wrote in an email. "In order to do this... they will necessarily always show speeds slightly in excess of actual speeds."

While speedometers are calibrated to fudge the numbers a little, odometers are designed to reflect accurate mileage, Tetzlaff says.

https://www.thrillist.com/cars/your-speedometer-is-wrong-speed-calibration-inaccuracy-in-german-american-and-japanese-cars:

For ordinary passenger vehicles, there’s no law in the U.S. that regulates speedometers, but U.S. manufacturers (and most Japanese as well) subscribe to a standard called SAE J1226. Your speedometer reading must be within a range of plus or minus four percent off, ....

Now it gets really crazy. The European Union requires adherence to UN ECE Regulation 39. It’s a lot of math, but the simple version is that no speedometer can read slower than the actual speed. Ever. On the high side, it’s allowed to read up to 10% above the actual speed plus four or six kilometers per hour, depending on the type of vehicle.

 

[jaapv]

Actually Andrev has a point here

I understand that in the past it was not possible to have high accuracy on the speedometer, and due to law/regulations car manufacture have been forced to add en error and show always speed above the real one.

But now, every car has GPS on board, and GPS is quite accurate on reading the real speed ... and the car could be tuned in real time to always show the real car speed (even inside a tunnel without GPS signal)

I think ... car manufacture got used to show speed in excess .. and possibly also driver got used to drive a bit faster since they know that the speedometer show an overestimated speed ...

But maybe it would be wise to change the law and regulations .. and force car manufactures to provide accurate with an error below 1% (as well ... countries should not punish people for have speed up to 1% above the speed limit ... I know most wise country and policeman do already ... but not everywhere and not every police man)

Policeman? Computer you mean. The positioning, accuracy and tolerance of speed checks are strictly defined by law.

 

[greendwarf]

Snowing in June! :lol:

 

[elm70]

Actually Andrev has a point here

I understand that in the past it was not possible to have high accuracy on the speedometer, and due to law/regulations car manufacture have been forced to add en error and show always speed above the real one.

But now, every car has GPS on board, and GPS is quite accurate on reading the real speed ... and the car could be tuned in real time to always show the real car speed (even inside a tunnel without GPS signal)

I think ... car manufacture got used to show speed in excess .. and possibly also driver got used to drive a bit faster since they know that the speedometer show an overestimated speed ...

But maybe it would be wise to change the law and regulations .. and force car manufactures to provide accurate with an error below 1% (as well ... countries should not punish people for have speed up to 1% above the speed limit ... I know most wise country and policeman do already ... but not everywhere and not every police man)

Policeman? Computer you mean. The positioning, accuracy and tolerance of speed checks are strictly defined by law.

Policemen

I saw tons of them in Austria and elsewhere with the radar speed gun in their hand and checking the traffic and eventually stopping cars

So, it is also a human decision too

 

[greendwarf]

But now, every car has GPS on board,

Might be true of new cars (since when?) but what about the millions of older ones and their drivers used to driving 5mph more than the speedo?

 

[kboczek]

So does anyone have programming instructions for the dealer? My Jetta was off same amount and got fixed.. My Charger was bang on... What happens when people want to totally change tire size and really need an ecm adjustment?

My dealer mentions analog vs digital but its hogwash as the cruise is digital when you set it and everything is fed through the ecm.

Does anyone know if the speed is taken of a single sensor on one of the axles or calculated from all the abs sensor inputs? If single sensor then a speedohealer will work. Then i could program actually two sizes if my winters are say different from the summers.

Everyone is talking about the issues but not a real fix for it.
Anyone have access to Mitsubishi software to dig into this?

 

[anko]

Everyone is talking about the issues but not a real fix for it.

Sorry, but isn't devising from the approved type size illegal? Over here, beyond a very small margin, it is.

BTW: I have found at least 10 different type of frames on the CANBUS from which you could drive speed. Each of them quite accurate. Question is: what frame is used by the dash?

 

[STS134]

I don't see a need to make the speedo show the wrong speed. Unlike the analog systems of the past, this is almost certainly a calculated speed from a computer, that is converted back to analog and shown on a gauge. The computer is probably more accurate than your eyes could tell by looking at the gauge.

In any case, I pretty much ignore my speedo. I drive as fast as I think is safe, and slow down if my radar detector or laser jammer alerts me. If the latter alerts me, I hit the brakes, get down to the speed limit, then kill the jammers to let the officer get my speed (now at the speed limit). I have the same system this guy talks about in the video (Antilaser Priority).

https://www.youtube.com/watch?v=v0W4UgivQ30

 

[greendwarf]

Hmm, glad I'm on this side of the pond. :?

 

[ThudnBlundr]

Quick thought for people happy to speed. Two identical vehicles are travelling along the road when one overtakes the other. One is doing 50mph and the other is doing 70mph as they pass eachother, when something pulls out of a hidden turning in front of them. The slower car manages to stop a few inches from the obstacle. If they both start braking at the same spot, how fast will the faster car be going when it reaches the obstacle.

You can work it out for yourselves, but I'll save you the trouble. The faster car will still be doing almost 50mph when it hits the obstacle. :shock: It's all to do with kinetic energy, as the faster car has double that of the slower car.

 

[STS134]

Quick thought for people happy to speed. Two identical vehicles are travelling along the road when one overtakes the other. One is doing 50mph and the other is doing 70mph as they pass eachother, when something pulls out of a hidden turning in front of them. The slower car manages to stop a few inches from the obstacle. If they both start braking at the same spot, how fast will the faster car be going when it reaches the obstacle.

You can work it out for yourselves, but I'll save you the trouble. The faster car will still be doing almost 50mph when it hits the obstacle. :shock: It's all to do with kinetic energy, as the faster car has double that of the slower car.

My previous car easily let me know that KE is proportional to v^2. I could literally almost STAND on the brake pedal @ 115 mph and it would feel like it was barely slowing at all. It was only when the speed got below around 95 that you could really feel the brakes working.

 

[jaapv]

I don't see a need to make the speedo show the wrong speed. Unlike the analog systems of the past, this is almost certainly a calculated speed from a computer, that is converted back to analog and shown on a gauge. The computer is probably more accurate than your eyes could tell by looking at the gauge.

In any case, I pretty much ignore my speedo. I drive as fast as I think is safe, and slow down if my radar detector or laser jammer alerts me. If the latter alerts me, I hit the brakes, get down to the speed limit, then kill the jammers to let the officer get my speed (now at the speed limit). I have the same system this guy talks about in the video (Antilaser Priority).

https://www.youtube.com/watch?v=v0W4UgivQ30

Which would have your car impounded over here,

 

[AllenPHEV]

Just want to add my voice to those who find this inaccuracy annoying, to say the least.
I'm over 60 and never had a car that much off.
For 2 weeks now, I own a 2018 GT model, and even the Cruise Control Digital display isn't accurate.
If I set it to 105 km/h, the analog display will show 108 km/h while the GPS's read 100 km/h.

I will have to check with my friend who own a non-PHEV Outlander or other Mitsubishi vehicle, but this inaccuracy will definitively push new PHEV Owner to drive slower than they did with their previous vehicle, and what really upset me, mislead them to believe they are using less gas/energy than they would do if driving at the real speed they were planning to do.

Anyhow, in a such technology advanced product, we should be able to get more accurate information.

 

[richr]

Anyhow, in a such technology advanced product, we should be able to get more accurate information.

The issue with measuring speed in a vehicle is the amount of information you've got to derive it. The best bet is to count wheel rotations -but the circumference of a wheel changes as the tyres wear or air pressure changes, so this can never be 100% accurate if you've got rubber tyres. Brand new tyres with a different chunky tread pattern will make the car travel further per rotation for example.
So wheel rotations are pretty accurate for things like trains, where wheels don't change size much. So unless manufacturers insist on everyone using the same make and type of tyre, at the same pressure and changing them as soon as they wear more than a set amount, the best they can do is err on the side of caution and introduce a tolerance - because as stated above, it's illegal in most countries for the speedometer to read slower than you're travelling.

GPS has its problems too - sample rates can be slow on non-specialist equipment, and the inherent inaccuracies can mount up. Most satnav type GPS systems work by assuming you're not leaving the road and average the position data to get a reasonably accurate speed indication. In areas with poor GPS reception, you've got nothing.

Inertial systems can help supplement GPS, but dead-reckoning on its own can be very inaccurate if you keep changing direction or altitude, so in some areas it can be useless too.

We've lived with speedometers reading up to 10% too fast for decades, so we might as well just live with it. It's even worse in planes and boats as you've got nothing fixed as a reference - so if you're moving into a headwind or current, it's very difficult to know your speed relative to a fixed point.

 

[greendwarf]

Just want to add my voice to those who find this inaccuracy annoying, to say the least.
I'm over 60 and never had a car that much off.
.

How do you know - GPS checking is relatively recent. :idea:

 

[jaapv]

Just want to add my voice to those who find this inaccuracy annoying, to say the least.
I'm over 60 and never had a car that much off.
For 2 weeks now, I own a 2018 GT model, and even the Cruise Control Digital display isn't accurate.
If I set it to 105 km/h, the analog display will show 108 km/h while the GPS's read 100 km/h.

I will have to check with my friend who own a non-PHEV Outlander or other Mitsubishi vehicle, but this inaccuracy will definitively push new PHEV Owner to drive slower than they did with their previous vehicle, and what really upset me, mislead them to believe they are using less gas/energy than they would do if driving at the real speed they were planning to do.

Anyhow, in a such technology advanced product, we should be able to get more accurate information.

My Jaguar before this was more off, and the Volvos I drove before that about the same as this (we had to calculate from the markers beside the road and a stopwatch )