actual speed of the car?
08-13-07, 03:34 PM
#1
Lexus Test Driver
Thread Starter
actual speed of the car?
ok I dunno if the built in nav system tells you your speed of the car, but I hooked up two different external gps to my car. It'll always be around 3-5mph slower than what my actual speedo says. Anybody else has this issue? I'm running on the summer ties the 245 something series.
Now I did the same test in a 07 ES Lexus loaner. I was off about 2-3mph slower than the speedo.
I tested it in my Sienna van, that one ran spot on. at all speeds.
This concerns me because if I set my cruz control at 65mph, i'm really doing about 60 or 61 which gets alot of poeople ticked. I set it at 70, and I would be closer to 65 but now I'm not sure if I'm really doing that. And thats not good. When posted speed is 55mph.
Now I did the same test in a 07 ES Lexus loaner. I was off about 2-3mph slower than the speedo.
I tested it in my Sienna van, that one ran spot on. at all speeds.
This concerns me because if I set my cruz control at 65mph, i'm really doing about 60 or 61 which gets alot of poeople ticked. I set it at 70, and I would be closer to 65 but now I'm not sure if I'm really doing that. And thats not good. When posted speed is 55mph.
08-13-07, 04:01 PM
#2
Lexus Test Driver
Join Date: Oct 2006
Location: Colorado
Posts: 1,201
Likes: 0
Received 0 Likes
on
0 Posts
that's about correct.
Without changing wheel size or tire diameter, the car runs about 3, but for me never as high as 4 or 5 mph...
But 3 mph slow is about accurate.
Example... I am driving 30, but my car says 27/28...
Without changing wheel size or tire diameter, the car runs about 3, but for me never as high as 4 or 5 mph...
But 3 mph slow is about accurate.
Example... I am driving 30, but my car says 27/28...
Trending Topics
08-13-07, 07:05 PM
#8
Lexus Test Driver
Join Date: Oct 2006
Location: NC- charlotte
Posts: 1,118
Likes: 0
Received 0 Likes
on
0 Posts
my friends scion t.c. did the same thing...also a toyota. he got a ticket doing "60" in a 45 zone when he speedo said 50. he fought and won his case by pleading speedometer miscalibration.
In my sc400, ive gone by those police things where it says speed limit xx, your speed xx and im usually 2-3 slower
In my sc400, ive gone by those police things where it says speed limit xx, your speed xx and im usually 2-3 slower
08-13-07, 07:48 PM
#9
Lexus Connoisseur
Every manufacturer has a variance in mileage +/- 2mph.
08-13-07, 10:24 PM
#10
Driver
Join Date: Jun 2007
Location: California
Posts: 187
Likes: 0
Received 0 Likes
on
0 Posts
DOT Specs
Believe it or not, the DOT standard for speedometer accuracy is 10% +2 mph. (At 60 MPH the speedo can read up to 68 MPH and still be within DOT specs.) Most all speedometers read on the fast side, some more than others. Speedometers are closer on cars than motorcycles. Most motorcycles read 10% fast.
08-14-07, 07:03 AM
#13
Driver
Join Date: Jun 2007
Location: California
Posts: 187
Likes: 0
Received 0 Likes
on
0 Posts
Reading Faster Than The Actual Speed
On a previous post you wrote "This concerns me because if I set my cruz control at 65mph, i'm really doing about 60 or 61 which gets alot of poeople ticked. I set it at 70, and I would be closer to 65 but now I'm not sure if I'm really doing that."
That means your speedo is reading faster than you are actually going.
That means your speedo is reading faster than you are actually going.
08-14-07, 09:14 AM
#15
my friends scion t.c. did the same thing...also a toyota. he got a ticket doing "60" in a 45 zone when he speedo said 50. he fought and won his case by pleading speedometer miscalibration.
In my sc400, ive gone by those police things where it says speed limit xx, your speed xx and im usually 2-3 slower
In my sc400, ive gone by those police things where it says speed limit xx, your speed xx and im usually 2-3 slower