speedo error
08-07-2011, 09:07 PM
#16
Rennlist Member
Based on the responses so far we can conclude:
A. Most if not all 996's speedo's read high.
B. The degree to which they read high probably is related to the year, model (C2 vs C4) and
C. The wheel and tire combinations giving various rolling circumferenci (just made that up as the plural of circumference).
D. Radar detector performance is totally subjective to how badly you have to justify/defend your purchase choice and price.
E. Radar guns in police trailer signs are fun to play with (until you find out that they actually also transmit a signal to a properly equipped local police car receiver, with a crosshair photo of the car it is locked onto at the moment).
A. Most if not all 996's speedo's read high.
B. The degree to which they read high probably is related to the year, model (C2 vs C4) and
C. The wheel and tire combinations giving various rolling circumferenci (just made that up as the plural of circumference).
D. Radar detector performance is totally subjective to how badly you have to justify/defend your purchase choice and price.
E. Radar guns in police trailer signs are fun to play with (until you find out that they actually also transmit a signal to a properly equipped local police car receiver, with a crosshair photo of the car it is locked onto at the moment).
08-08-2011, 12:59 AM
#17
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Based on the responses so far we can conclude:
D. Radar detector performance is totally subjective to how badly you have to justify/defend your purchase choice and price.
E. Radar guns in police trailer signs are fun to play with (until you find out that they actually also transmit a signal to a properly equipped local police car receiver, with a crosshair photo of the car it is locked onto at the moment).
D. Radar detector performance is totally subjective to how badly you have to justify/defend your purchase choice and price.
E. Radar guns in police trailer signs are fun to play with (until you find out that they actually also transmit a signal to a properly equipped local police car receiver, with a crosshair photo of the car it is locked onto at the moment).
I was driving down a 4 lane divided blvd very late (or was it very early) in the night (morning.) My 9500 went off, and as I always do, I tromped on the brake to get me down to speed limit. I had just finished passing a crotch rocket, and he went zipping past me as I braked. He slowed down as well, and for the better part of a mile, he paralleled me.
Then we both turned right onto another highway, and I was ready to turn left into the parking lot. The rocketeer twisted around on his seat to see what was following us (if anything). Just then, I turned left, and he accelerated. Right behind me was a PD SUV accelerating past me towards the crotch rocket.
I never figured out why he paced me for so long and then took off. Was he thinking that he was going to outrun the SUV PD Car? Didn't he recognize that this was a police car, and he thought I was just driving slowly for the hell of it? Ah, yes, we will never know. But my Escort 9500ix had saved my butt again, just as it has done dozens of times. Thanks, I don't have a real need to justify my purchase to you guys. I have already justified it to myself 4 - 5 times a week over the 3 months that I've had it.
larry
08-08-2011, 02:47 AM
#18
Racer
IIRC, plugging into the OBD-II port, the "Vehicle Speed" parameter gives you the correct (higher) reading compared to the speedo. (My memory is a little hazy, so i could easily be wrong)
R
08-08-2011, 10:11 AM
#19
Pro
Thread Starter
Oh, yes, a radar detector thread is just about as universal as an oil thread.
I was driving down a 4 lane divided blvd very late (or was it very early) in the night (morning.) My 9500 went off, and as I always do, I tromped on the brake to get me down to speed limit. I had just finished passing a crotch rocket, and he went zipping past me as I braked. He slowed down as well, and for the better part of a mile, he paralleled me.
Then we both turned right onto another highway, and I was ready to turn left into the parking lot. The rocketeer twisted around on his seat to see what was following us (if anything). Just then, I turned left, and he accelerated. Right behind me was a PD SUV accelerating past me towards the crotch rocket.
I never figured out why he paced me for so long and then took off. Was he thinking that he was going to outrun the SUV PD Car? Didn't he recognize that this was a police car, and he thought I was just driving slowly for the hell of it? Ah, yes, we will never know. But my Escort 9500ix had saved my butt again, just as it has done dozens of times. Thanks, I don't have a real need to justify my purchase to you guys. I have already justified it to myself 4 - 5 times a week over the 3 months that I've had it.
larry
I was driving down a 4 lane divided blvd very late (or was it very early) in the night (morning.) My 9500 went off, and as I always do, I tromped on the brake to get me down to speed limit. I had just finished passing a crotch rocket, and he went zipping past me as I braked. He slowed down as well, and for the better part of a mile, he paralleled me.
Then we both turned right onto another highway, and I was ready to turn left into the parking lot. The rocketeer twisted around on his seat to see what was following us (if anything). Just then, I turned left, and he accelerated. Right behind me was a PD SUV accelerating past me towards the crotch rocket.
I never figured out why he paced me for so long and then took off. Was he thinking that he was going to outrun the SUV PD Car? Didn't he recognize that this was a police car, and he thought I was just driving slowly for the hell of it? Ah, yes, we will never know. But my Escort 9500ix had saved my butt again, just as it has done dozens of times. Thanks, I don't have a real need to justify my purchase to you guys. I have already justified it to myself 4 - 5 times a week over the 3 months that I've had it.
larry
08-08-2011, 10:32 AM
#20
Racer
Join Date: Jun 2010
Location: Eastern PA
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My car is 4mph faster.
I believe this is so you can change tire sizes and never read a speed slower than you are going.
As for the 8500 vs 9500 I beleive from my research (i'm looking to upgrate my old K40) uses gps to remember false readings. But I beleive the range is equal for both detectors. So if you live someplace that you get lots of false readings consider the 9500. I believe it is the best on the market right now. But the 8500 is a couple hundred $ cheaper. FWIW I'm leaning toward the 8500 based on the places I drive.
I believe this is so you can change tire sizes and never read a speed slower than you are going.
As for the 8500 vs 9500 I beleive from my research (i'm looking to upgrate my old K40) uses gps to remember false readings. But I beleive the range is equal for both detectors. So if you live someplace that you get lots of false readings consider the 9500. I believe it is the best on the market right now. But the 8500 is a couple hundred $ cheaper. FWIW I'm leaning toward the 8500 based on the places I drive.
08-08-2011, 05:42 PM
#22
Race Director
The speed error will vary depending upon speed and can change a bit over time as tires wear and if so then when you replace tires or possibly if you switch to a different tire.
I've calibrated/characterized my cars' speedos well enough if conditions permit I'll pass a police or highway patrol car that is going just under the limit with no fear. And so far I've never been stopped.
Sincerely,
Macster.
08-08-2011, 08:16 PM
#23
Pro
Thread Starter
Best bet is to get a good GPS handheld or NAV unit (I've used both having a NAV unit now) or something to connect to the OBD2 port and view your vehicle's speed in real time to 'calibrate' your car's speedo.
The speed error will vary depending upon speed and can change a bit over time as tires wear and if so then when you replace tires or possibly if you switch to a different tire.
I've calibrated/characterized my cars' speedos well enough if conditions permit I'll pass a police or highway patrol car that is going just under the limit with no fear. And so far I've never been stopped.
Sincerely,
Macster.
The speed error will vary depending upon speed and can change a bit over time as tires wear and if so then when you replace tires or possibly if you switch to a different tire.
I've calibrated/characterized my cars' speedos well enough if conditions permit I'll pass a police or highway patrol car that is going just under the limit with no fear. And so far I've never been stopped.
Sincerely,
Macster.
I have a Garmin with indicated speed. I just didn't think it was accurate.
08-09-2011, 12:14 PM
#25
Three Wheelin'
08-09-2011, 05:44 PM
#30
Race Director
No light bar lights on. No weaving like they do during a traffic break. The road ahead looked ok to me. So I put the car's speed at a true 65mph and drove on past.
Some years ago I encountered what I thought was a state police car on I-40 crossing the Texas panhandle east of Amarillo TX. It looked 'official' (Crown Vic) and was all black but looked like some kind of plains clothes car to me. No light bar on the roof.
Another driver in another car and I had been making 'good' time until the black car showed up. Of course we both slowed down to the limit. I suspected the black car was a ground unit for a bear in the air speed trap but the black car never put on what I suspected was an inside the car light bar nor made any signs of wanting either of us to pull over.
After some time both the other driver and I ended up with our cars in the slow lane with me behind the other driver and his car.
The black car then slowly, ever so slowly, came up in the fast lane. It paced my car a bit then moved up to the other driver's car.
When the black car got a bit ahead of my car I spotted the 'Interdiction' lettering on the back.
The black car's speed slowly dropped and the driver of the car ahead of mine slowed his car's speed to match the speed of the black car.
For a bit of time (it seemed like ages) all 3 cars moved at something under the posted limit.
I went along with this for a while but since I was clean (of course) and had nothing to fear even if I was pulled over I sped my car up to the limit and pulled out in the fast lane and the black car then pulled over into the slow lane ahead of the other car and in not too much time I left both the black car and the other driver and his car behind me.
As long as I could I sneaked a glance in the rear view mirror expecting to see the other driver and his car pulled over but I never saw this and since I was now making the speed limit the other cars were soon out of sight.
Sincerely,
Macster.