Accepted Speedo error
- Thread starter Monkeyballs
- Start date
Well, keep in mind there is a hard speed limit here at 75 on I-25. And they are pretty rabid about enforcing the 45 in the construction zone. However, they are banned from giving tickets for less than 5 over.
I agree that driver ability is very importaint. Thats why I think driver education needs to be stepped waaaayyyy up from where it is now. You should not be able to pass a drivers test from just piddling around some simple city streets. Drivers tests should cover things like skid recovery and emergency manuvering. Also, I cant tell you how many accidends I see around colorado from people driving in the snow that are unfamiliar with how a car handles near its traction limit.
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- DC
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- 03 Protege ES
a co-worker of mine said he went to the dealer and asked to check the speedo to try and get out of the ticket. the tech said they're good for the life of the car (unless there are some kind of mod like wheel/tire). its a different mfg...i think benz, so i dunno. the tech could also just be makin excuses so he didn't have to work on my co-worker's car. worst case: plead no contest or guilty. the judge may just reduce the fine or drop charges all together if you maybe explained to him/her you thought 4 over was a safe limit set on your cruise control. the courts usually dont deal with points so they wont be able to help you in that area.
kickniteasy
Member
QFT
My sister actually is about to get her permit in a couple of weeks in CO and is taking the class over the cpu. Yeah, driver's ed over a computer is really going to help when she gets behind the wheel. What ever happened to at least having driver's ed in an empty high school parking lot.....at least that involved cars.
i dono but if i were the judge, i would ask you why you thought 69 was a safe limit when it clearly says that the limit is 65 and that it against the law to go over the speed limit. you even admitted to be going 69.
but i'm not a judge and always go over the limit
on another note ... the speedometer ALWAYS reads higher than the speed you are actually going. i guess its some kind of safety measure to make you think you're going faster than you actually are. I know that when i'm doing 130km/h my speedo reads about 134km/h ... you can find this out by getting the speed reading directly from the ecu. If you changed tire size, than the reading from the ecu is wrong to start with so there's no point in check any of this ... but with stock wheels/tire, the actual speed is about 3% under the speedo speed. so you set your cruise control at 69 based on the speed you saw on your speedometer right? you were actually maybe doing only 67
but i'm not a judge and always go over the limit
on another note ... the speedometer ALWAYS reads higher than the speed you are actually going. i guess its some kind of safety measure to make you think you're going faster than you actually are. I know that when i'm doing 130km/h my speedo reads about 134km/h ... you can find this out by getting the speed reading directly from the ecu. If you changed tire size, than the reading from the ecu is wrong to start with so there's no point in check any of this ... but with stock wheels/tire, the actual speed is about 3% under the speedo speed. so you set your cruise control at 69 based on the speed you saw on your speedometer right? you were actually maybe doing only 67
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It depends on the tread wear on your tires. It may come from the factory 1.5% slow but when your tires are at 50% wear it might be dead on...and when your tires are bald it might be 1.5% fast.
A 195/55/16 tire is 3.2% slower than a 195/50/16 (stock P5 tire size). It works out to be a difference of about 3/4" in diameter. Divide that in half and you'll get a number that is pretty close to the full tread on most all-season tires.
So drive60MPH in a 65 zone...that will guarantee that you are under the limit regardless of your treadwear (assuming you have the proper sized tires). Otherwise, take your chances with the local law enforcement.
A 195/55/16 tire is 3.2% slower than a 195/50/16 (stock P5 tire size). It works out to be a difference of about 3/4" in diameter. Divide that in half and you'll get a number that is pretty close to the full tread on most all-season tires.
So drive60MPH in a 65 zone...that will guarantee that you are under the limit regardless of your treadwear (assuming you have the proper sized tires). Otherwise, take your chances with the local law enforcement.
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- Protege5 2003
chuyler1 said:
Perhaps, but then you'll be hit from behind with a speed difference of at least 15 mph, as opposed to only the 10 mph it would have been if you have been driving right at the speed limit.
Most people don't get rear-ended at full speed unless it's by someone going 20 or 30+ miles over the limit driving recklessly. Worst case scenario is that some one comes up behind you fast, attempts to switch lanes and accidentally clips aonther car or freaks out an SUV driver who attempts to make a swift lane change and rolls into a ditch instead. Meanwhile you just cruise along at 60mph unaware that you caused a 10 car pile up.
mogi said:
i read that the tach and speedo read higher than actual numbers to fool us into thinking we're driving lets say 70mph when we're actually doing 65 or that we're revving at 7000 while its actually revving at 6800 ... i think it was on this forum, can't remember who/when this was though
how did you find out yours read 2% slower ?
ZeroAccess
Member
My sister just got her liscense and is a decent driver but the cool thing is she took a drivers ed test in a squad car. They had her drive in wet conditions (got a firetruck and soaked the parking lot) and all types of stuff. I didn't get to see it but she told me all about it. Hell I'm 22 and I think it'd be a blast and I could learn a lot from doing that. Skid Control, Emergency Situations,Etc,etc. I agree though that its rediculous how low our driving test are BUT I also remember when I was 16 and when I got my liscense I was out tearing the roads up like 24hrs straight with ALL my friends cramped in the car. My sister can't even go to the local 7-11 with ONE friend in the car.
Sucks...
Sucks...
I can definetly see that happening here in colorado on I-25. The interstate speed limit is 75 even at night. If Im cruising along in southern colorado at between 75-80, I usually come up on trucks going around 50. Im ususally able to react and switch lanes in plenty of time, but I could easily see a rear ending accident from someone less on top of things.
Ive heard the number one cause of freeway accidents is speed differentials. I think the best speed is what everyone else is doing.
Metal MP5 said:
I tried explaining it earlier in the thread. Use your trip odometer, the mile markers along the highway, your speedometer, and a stopwatch. You can compare your trip to the mile markers, and calculate speed/distance differences with the speedometer and stop watch.
I did this over multiple stretches of road at multiple speeds to try and reduce errors. I came out at 2% damn near every time.
