How accurate is the speedo? - Page 2 - LotusTalk

MikeC · 07-11-2006, 03:43 PM

Well.. today my speedo got worse.. I was going slow.. about 30 and I watched it creep up to 60. And now, it rests at 1o mph when the car is stopped. To me, the speedo is important for a road car. They need to fix it. I sure hope its fixable. I can't believe they expect everyone to put up with a broken speedometer.

andykeck · 07-11-2006, 04:06 PM

Quote:

Originally Posted by MikeC

Well.. today my speedo got worse.. I was going slow.. about 30 and I watched it creep up to 60. And now, it rests at 1o mph when the car is stopped. To me, the speedo is important for a road car. They need to fix it. I sure hope its fixable. I can't believe they expect everyone to put up with a broken speedometer.

The needle reset procedure is in the manual. Otherwise, if the gauge is truly broken, then obviously that'll get swapped out under warranty. But the new one will read 7 to 8 percent high too.

MikeC · 07-11-2006, 04:47 PM

Quote:

Originally Posted by andykeck

The needle reset procedure is in the manual. Otherwise, if the gauge is truly broken, then obviously that'll get swapped out under warranty. But the new one will read 7 to 8 percent high too.

Thanks! that worked. Now the needle is at zero. Does anyone know why it gets out of sync? I"ll check its accuracy tomorrow with my GPS

Baysailor · 07-11-2006, 05:15 PM

Quote:

Originally Posted by MikeC

Thanks! that worked. Now the needle is at zero.

Does yours rest exactly at zero or is it above it? Mine rests right around 2~3 MPH, but other than that is within the norm (7% or so off).

MikeC · 07-11-2006, 05:24 PM

Mine reset actually a hair below zero.

So, you think that if I complain about it, it cannot be fixed?

charliex · 07-11-2006, 05:27 PM

I think the more you complain about it, the less likely it is they'll fix it.

As i said earlier my 1991 elan has the same thing, Lotus never fixed that either.

It'd need a stateside cluster, seems unlikely they'd do it as the clusters most likely come like that when they buy them in, its not really a lotus defect.

ct20b drifter · 07-24-2006, 11:05 PM

i used to have an mr2 with wheels larger than stock, that caused my speedo to be innaccurate. i was actually going ~6-7% faster than the speedo was reading. although it's the opposite problem (the lotus speedo is reading faster than actual speed). basically, you guys need to swap to larger rims to get accurate readings but it wont be reflected by the GPS.

Jack · 07-25-2006, 06:34 AM

Quote:

Originally Posted by charliex

jack says the 06 is fine, i haven't comapared mine yet.

My Exige Speedo was pretty close to accurate as compared to my '05 Elise. The '05 was fast by about 7-8% -- not my '06.

onecall1 · 07-25-2006, 07:40 AM

How can the speedo be off (which mine is) but the odometer be on? Are these two not tied together? Stumped.

TimMullen · 07-25-2006, 07:46 AM

Quote:

Originally Posted by ct20b drifter

basically, you guys need to swap to larger rims to get accurate readings but it wont be reflected by the GPS.

Except that will be detrimental to the acceleration, braking, and handling of the car. Additionally, it may make the speedometer more accurate, but the odometer will not longer be accurate...

Tintin · 07-25-2006, 10:01 AM

Quote:

Originally Posted by onecall1

How can the speedo be off (which mine is) but the odometer be on? Are these two not tied together? Stumped.

My understanding is that the ECU sends the correct info to the instrument cluster. Somebody here on Elisetalk had attached a scanner to the bus (canbus?) and figured out that it matched their GPS reported speed. Its the instrument cluster that decides to move the speedo needle 7-8% too much. Thats how the odometer can be accurate but not the speedo.

charliex · 07-25-2006, 10:07 AM

The odometer uses a seperate source for its information, not just the CAN bus, that would be catastrophic.

There is another microcontroller in the cluster that has the error introduced.

nvrblu · 07-25-2006, 10:17 AM

Is the speedometer needle driven by a galvanometer or a servo motor? If it's a galvanometer, it could probably be adjusted by adding or adjusting a shunt resistor. The speed sensor is digital... the guage is analog.

I checked mine against a gps and found 80 mph on the speedo was really 76. Not much to worry about but nice to know.

MikeC · 07-25-2006, 10:56 AM

Yes.. I agree. 76 vs an indicated 80 would be quite acceptable to me.

But in my car an indicated 80 is actually 61. thats pretty far off.

The other issue I have is that my needle does not reset to zero. It is now resting at 15 MPH. It zeros when I do the RESET procedure, but in a few days it's back at 15-20 MPH again.

Is RESET something you need to do often? like every other day?

andykeck · 07-25-2006, 10:59 AM

Quote:

Originally Posted by MikeC

Is RESET something you need to do often? like every other day?

Over 13,000 miles and I've never had to do the reset procedure. I think yours is just plain broken.

JimG · 08-29-2006, 05:03 PM

My speedo ('06 Exige) seems accurate when I start out, then after a while on the highway it slowly decays to reading slower and slower. The worst I've seen is probably 20 mph below actual, judging by the tach. When I come to a complete stop it seems to be ok again for a while.

It's going in for service this week and the dealer said they will repalce the gauge set if the reset procedure doesn't solve the issue. There must be some Lucas electronics somewhere in there.

gameson · 04-21-2007, 12:37 AM

my speedometer is off by ~+8 mph across all speed (so if it's 70 mph on the tach, GPS reads about 62 mph). I compared it with my GPS speed

Zerofail · 04-21-2007, 06:46 AM

+8 on mine as well. I am not sure it is a big enough deal for me to have fixed.

carl · 04-21-2007, 09:00 AM

my S read 151 @148mph on the GPS above 95 its dead on, 3-4mph high below 90. carl

Jack · 04-21-2007, 05:18 PM

Quote:

Originally Posted by 4carl

my S read 151 @148mph on the GPS above 95 its dead on, 3-4mph high below 90. carl

My experience as well with all my cars that were '06 or later. The 2005 Elise speedos were fast by ~ 7-8%. 120 MPH was actually ~111 MPH

07-11-2006, 03:43 PM	#21 (permalink)
MikeC Registered User Join Date: Jun 2006 Posts: 218	Well.. today my speedo got worse.. I was going slow.. about 30 and I watched it creep up to 60. And now, it rests at 1o mph when the car is stopped. To me, the speedo is important for a road car. They need to fix it. I sure hope its fixable. I can't believe they expect everyone to put up with a broken speedometer. __________________ Keep the shiny side up MikeC 05 CO Elise 02 Audi S6 72 MB 280SE 4.5

07-11-2006, 05:24 PM	#25 (permalink)
MikeC Registered User Join Date: Jun 2006 Posts: 218	Mine reset actually a hair below zero. So, you think that if I complain about it, it cannot be fixed? __________________ Keep the shiny side up MikeC 05 CO Elise 02 Audi S6 72 MB 280SE 4.5

07-11-2006, 05:27 PM	#26 (permalink)
charliex OSX Black hat Join Date: Feb 2005 Location: Las Vegas , NV Posts: 9,935	I think the more you complain about it, the less likely it is they'll fix it. As i said earlier my 1991 elan has the same thing, Lotus never fixed that either. It'd need a stateside cluster, seems unlikely they'd do it as the clusters most likely come like that when they buy them in, its not really a lotus defect. __________________ Black Exige S - http://goth.am 265 Mule / Elan M100.ECU Tuning, http://www.elisetalk.com/forums/showthread.php?t=39660 West Coast Lotus Meet - Las Vegas - November 6-9 2009 http://www.westcoastlotus.com/

07-25-2006, 07:40 AM	#29 (permalink)
onecall1 Registered User Join Date: Jan 2006 Location: Grand Island, NY Posts: 127	How can the speedo be off (which mine is) but the odometer be on? Are these two not tied together? Stumped. __________________ Former Elise and Esprit owner. Currently enjoying my M3 purchased from HRM.

07-25-2006, 10:07 AM	#32 (permalink)
charliex OSX Black hat Join Date: Feb 2005 Location: Las Vegas , NV Posts: 9,935	The odometer uses a seperate source for its information, not just the CAN bus, that would be catastrophic. There is another microcontroller in the cluster that has the error introduced. __________________ Black Exige S - http://goth.am 265 Mule / Elan M100.ECU Tuning, http://www.elisetalk.com/forums/showthread.php?t=39660 West Coast Lotus Meet - Las Vegas - November 6-9 2009 http://www.westcoastlotus.com/

07-24-2006, 11:05 PM	#27 (permalink)
ct20b drifter Registered User Join Date: May 2006 Posts: 31	i used to have an mr2 with wheels larger than stock, that caused my speedo to be innaccurate. i was actually going ~6-7% faster than the speedo was reading. although it's the opposite problem (the lotus speedo is reading faster than actual speed). basically, you guys need to swap to larger rims to get accurate readings but it wont be reflected by the GPS.

07-25-2006, 10:17 AM	#33 (permalink)
nvrblu ... _ . ..._ . Join Date: Jan 2006 Location: Mesa, AZ Posts: 3,386	Is the speedometer needle driven by a galvanometer or a servo motor? If it's a galvanometer, it could probably be adjusted by adding or adjusting a shunt resistor. The speed sensor is digital... the guage is analog. I checked mine against a gps and found 80 mph on the speedo was really 76. Not much to worry about but nice to know.

07-25-2006, 10:56 AM	#34 (permalink)
MikeC Registered User Join Date: Jun 2006 Posts: 218	Yes.. I agree. 76 vs an indicated 80 would be quite acceptable to me. But in my car an indicated 80 is actually 61. thats pretty far off. The other issue I have is that my needle does not reset to zero. It is now resting at 15 MPH. It zeros when I do the RESET procedure, but in a few days it's back at 15-20 MPH again. Is RESET something you need to do often? like every other day? __________________ Keep the shiny side up MikeC 05 CO Elise 02 Audi S6 72 MB 280SE 4.5

08-29-2006, 05:03 PM	#36 (permalink)
JimG Registered User Join Date: Aug 2006 Location: Manhattan Beach, CA Posts: 91	My speedo ('06 Exige) seems accurate when I start out, then after a while on the highway it slowly decays to reading slower and slower. The worst I've seen is probably 20 mph below actual, judging by the tach. When I come to a complete stop it seems to be ok again for a while. It's going in for service this week and the dealer said they will repalce the gauge set if the reset procedure doesn't solve the issue. There must be some Lucas electronics somewhere in there.

04-21-2007, 12:37 AM	#37 (permalink)
gameson Track Addict Join Date: Mar 2006 Posts: 1,999	my speedometer is off by ~+8 mph across all speed (so if it's 70 mph on the tach, GPS reads about 62 mph). I compared it with my GPS speed

04-21-2007, 06:46 AM	#38 (permalink)
Zerofail Registered User Join Date: Apr 2007 Posts: 81	+8 on mine as well. I am not sure it is a big enough deal for me to have fixed. __________________ 05 ST Elise (Current) 07 Toyota FJ Cruiser (current) 65 Mustang (current) 02 MINI Cooper S (sold) 71 Land Rover Series II 109 Wagon (sold) 67 Camaro RS/SS (sold) 60 Austin Healy Bugeye (Full on "John P Lucas Prince of Darkness wirring (sold)

04-21-2007, 09:00 AM	#39 (permalink)
carl Registered User Join Date: Oct 2005 Posts: 1,050	my S read 151 @148mph on the GPS above 95 its dead on, 3-4mph high below 90. carl

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