i installed Superchip tuner 1714.

I set everything superchips "87", 3.73, tire height 31.50" and i finally used my GPS and it read that my truck MPH gauge is 4-5MPH faster...

GPS reads 65mph and gauge read 69-70mph.

WTF ? My 18" tires is 31.5" so i reduced to 31.25" thru superchip tuner set and it now down to 1-2MPH off and call it nite cuz i m a bit tired from work all day..

Could i reduce to 31.00" thru superchip tuner or leave it 31.25" ? I will test 31" and compare w/ my GPS.

i checked my tires and they all are at 35-36psi.

Any feedback ? If 1-2mph off is common then i ll okay with it


Thanks!
YOMAN!
2004 screw FX4 3.73

 

Check out this thread:
https://www.f150online.com/forums/sh...hreadid=178764

 

1-2 mph aint a big deal.

 

Leave it, perhaps it will save you a speed ticket one day.:santa:

 

Hehe i m not a heavy foot...i guess i ll try reduce tire height to 31.00 and see what happen..

Thanks!
YOMAN!

 

When it asks the tire height and axle size, just hit stock.

I tried to input the setting in myself,(30.5" tires, 3.55 rear axle), and it threw my speedo way off. I didnt even notice it for a couple of days, then while I was cruzing at "70" the RMPS were way to low. I knew then it was off. I re-tuned it with Stock truck setting, except Hi-Proformance tune, and its all fine now.

 

don't change anything, if it's all stock dont start pressing
buttons it knows what you have, unless you change
gear or tire u don't need to put in tire size,
i have one ez to install, spedo is not off.
but mt truck is still faster than yours.

 

My 04 super cab 4X4 FX4 is the same way. I checked it with three GPS’s simultaneously and all read 4 – 5 miles per hour faster. I also set the trip in the truck and the trips in the GPS’s and the mileage was bang on but the needle wasn’t. I mentioned it to Ford, but they had no answers. I am not worried too much about it; at least it keeps me a little slower than I think I am going and hopefully no tickets!

 

did you check your speed with the gps befor the mods my gps reads about 4 mph different then my stock truck ive checked it in other vehicles to so i know its the gps thats off a little

 

YEah i just pressed (superchip tuner) to set stock gear and tire and leave it alone..

my GPS read 1-2 mph off.

I was told that GPS can be a bit off.

I m thinking about order Scangauge

Thanks!

YOMAN!

 

My scangauge reads 65MPH when the speedo is at around 67.5MPH. Haven't tried with a GPS yet I would think the GPS would be closer to actual speed. Usually auto and motorcycle manufacturers put in a 3-5% error to read high on the vehicle's speedo to avoid lawsuits from people getting tickets for speeding when they are at the limit on their speedo.
Unless you bought one of those honda CBR600RR's that were reading slower than your actual speed by 5-10%