Go Back   Ford Truck Enthusiasts Forums > Diesel > 6.7L Power Stroke Diesel
Sign in using an external account
Register Forgot Password?


6.7L Power Stroke Diesel 2011-2015 Ford Powerstroke 6.7 L turbo diesel engine

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 04-07-2014, 09:20 PM
Ltngdrvr's Avatar
Ltngdrvr Ltngdrvr is online now
Senior User
 
Join Date: Nov 2005
Posts: 333
Ltngdrvr is gaining momentum as a positive member of FTE.
Tires and Speedometer accuracy...

Speedometer has been off in my truck ever since it was new. Had the dealer check on it and was told it was within the spec range so ford wouldn't do anything about it. According to my GPS, the speedo is off by a little over 2 mph at an indicated 70, about 3.5%.

Today I went and bought some new tires, went up to a 285/70R17 from the oem 245/75R17 size.

My speedo is now almost perfectly on the money, maybe a half needle width off at 70 now.

This of course has also lowered the rpm's a little for a given speed.

Hope this all translates to a little better mpg's...
__________________

My 2012 F250 and Cougar Xlite
Reply With Quote
  #2  
Old 04-07-2014, 09:55 PM
kper05's Avatar
kper05 kper05 is offline
Postmaster
 
Join Date: Jan 2010
Location: AL
Posts: 4,860
kper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant future
Check the speed in engineer mode. Before, it was probably close to exact.
The speedometer is programmed to be fast. That was my experience with OEM tires.
Now your truck is probably reporting slower than it is even though your speedometer now appears more accurate.
__________________
2011 F-250 XLT SC SB 4x4 3.31 ELD 6.7L PSD JOB-1 (05/10)
Reply With Quote
  #3  
Old 04-07-2014, 09:59 PM
Ltngdrvr's Avatar
Ltngdrvr Ltngdrvr is online now
Senior User
 
Join Date: Nov 2005
Posts: 333
Ltngdrvr is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by kper05 View Post
Check the speed in engineer mode. Before, it was probably close to exact.
The speedometer is programmed to be fast. That was my experience with OEM tires.
Now your truck is probably reporting slower than it is even though your speedometer now appears more accurate.
I check it by the GPS that I know to be very accurate.
__________________

My 2012 F250 and Cougar Xlite
Reply With Quote
  #4  
Old 04-07-2014, 10:06 PM
kper05's Avatar
kper05 kper05 is offline
Postmaster
 
Join Date: Jan 2010
Location: AL
Posts: 4,860
kper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant future
By truck I meant truck computer, not the speedometer.
Your GPS matches your speedometer now but you truck is now wrong.
That's my experience.

With OEM tires, my speedometer was off like yours but the truck speed matched two GPS units.
__________________
2011 F-250 XLT SC SB 4x4 3.31 ELD 6.7L PSD JOB-1 (05/10)
Reply With Quote
  #5  
Old 04-08-2014, 07:37 AM
U235Fishin' U235Fishin' is offline
Senior User
 
Join Date: Jan 2013
Location: New Mexico
Posts: 110
U235Fishin' is gaining momentum as a positive member of FTE.U235Fishin' is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by Ltngdrvr View Post
Speedometer has been off in my truck ever since it was new. Had the dealer check on it and was told it was within the spec range so ford wouldn't do anything about it. According to my GPS, the speedo is off by a little over 2 mph at an indicated 70, about 3.5%.

Today I went and bought some new tires, went up to a 285/70R17 from the oem 245/75R17 size.

My speedo is now almost perfectly on the money, maybe a half needle width off at 70 now.

This of course has also lowered the rpm's a little for a given speed.

Hope this all translates to a little better mpg's...
As compared to two GPS's that nearly match, my speedometer has always indicated about 2.5 mph high at 65 mph with the stock Michelins.
__________________
2012 F250 XLT, 6.7L, 4x4, CCSB, 3.31 ELD, 18" wheels, ScanGaugeII, SnugTop cab high shell, Rancho RS9000XL shocks, Air Lift bags & WirelessOne compressor, 25' Arctic Fox TT, anemic 26 gal tank

Last edited by U235Fishin'; 04-08-2014 at 07:39 AM. Reason: add info
Reply With Quote
  #6  
Old 04-08-2014, 08:57 AM
Ltngdrvr's Avatar
Ltngdrvr Ltngdrvr is online now
Senior User
 
Join Date: Nov 2005
Posts: 333
Ltngdrvr is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by kper05 View Post
By truck I meant truck computer, not the speedometer.
Your GPS matches your speedometer now but you truck is now wrong.
That's my experience.

With OEM tires, my speedometer was off like yours but the truck speed matched two GPS units.
I don't understand, the truck is "now wrong" ???

It was "wrong" before with the stock size tires, and now has been corrected with the taller tires, now the speedometer matches the accurate GPS readout.
__________________

My 2012 F250 and Cougar Xlite
Reply With Quote
  #7  
Old 04-08-2014, 09:00 AM
Ltngdrvr's Avatar
Ltngdrvr Ltngdrvr is online now
Senior User
 
Join Date: Nov 2005
Posts: 333
Ltngdrvr is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by U235Fishin' View Post
As compared to two GPS's that nearly match, my speedometer has always indicated about 2.5 mph high at 65 mph with the stock Michelins.
Yes, exactly what my situation was before adding the taller tires.

I believe ford purposely sets the speedometer up to read fast, causing miles to accrue quicker on the odometer, making the warranty miles run out sooner.
__________________

My 2012 F250 and Cougar Xlite
Reply With Quote
  #8  
Old 04-08-2014, 10:22 AM
720Deere's Avatar
720Deere 720Deere is online now
Postmaster
 
Join Date: Sep 2006
Location: Maryland
Posts: 2,537
720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future
Actually most people find that the odometer reads several percent low on the 2011+ trucks.
__________________
Matt

2011 F-350 FX4 Ultimate Lariat CC LB 3.55 w/factory 20s
Reply With Quote
  #9  
Old 04-08-2014, 11:15 AM
Ltngdrvr's Avatar
Ltngdrvr Ltngdrvr is online now
Senior User
 
Join Date: Nov 2005
Posts: 333
Ltngdrvr is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by 720Deere View Post
Actually most people find that the odometer reads several percent low on the 2011+ trucks.
Every person I've talked to or read forum comments from has claimed just the opposite, like me their truck's speedometer reads faster than actual mph and of course the odometer is fast too.

My dad's new F350 also reads fast.
__________________

My 2012 F250 and Cougar Xlite
Reply With Quote
  #10  
Old 04-08-2014, 11:40 AM
F stock owner F stock owner is offline
Junior User
 
Join Date: Apr 2013
Location: San Francisco Bay Area
Posts: 92
F stock owner is starting off with a positive reputation.
The speedometer on my all stock-OEM Michelins 2012 F-350 has always been right on the money as indicated by two handheld GPS units and roadside radar speed signs. I like the idea of going into engineering mode to see what the computer actually "thinks" the speed is compared to the speedometer. I'll have to try to remember that.
---

2012 F-350 Lariat 6.7 CC SRW LB
Reply With Quote
  #11  
Old 04-08-2014, 06:48 PM
kper05's Avatar
kper05 kper05 is offline
Postmaster
 
Join Date: Jan 2010
Location: AL
Posts: 4,860
kper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant futurekper05 has a brilliant future
The point I'm attempting to make is the truck speed and speedometer are two separate readings.
By truck, I mean the truck computer (that you cannot see in normal mode).
My understanding, mileage, MTE, etc. read off the truck computer speed not the gauge.

http://www.ford-trucks.com/forums/10...ml#post9695824
__________________
2011 F-250 XLT SC SB 4x4 3.31 ELD 6.7L PSD JOB-1 (05/10)
Reply With Quote
  #12  
Old 04-08-2014, 07:01 PM
720Deere's Avatar
720Deere 720Deere is online now
Postmaster
 
Join Date: Sep 2006
Location: Maryland
Posts: 2,537
720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future720Deere has a brilliant future
Quote:
Originally Posted by Ltngdrvr View Post
Every person I've talked to or read forum comments from has claimed just the opposite, like me their truck's speedometer reads faster than actual mph and of course the odometer is fast too.

My dad's new F350 also reads fast.
You think that the speedometer and the odometer have to be calibrated the same.....how cute.
__________________
Matt

2011 F-350 FX4 Ultimate Lariat CC LB 3.55 w/factory 20s
Reply With Quote
  #13  
Old 04-08-2014, 07:03 PM
GridLine's Avatar
GridLine GridLine is offline
Junior User
 
Join Date: Mar 2014
Posts: 58
GridLine is starting off with a positive reputation.
I drove by a roadside speed radar yesterday. The speedometer was right at 45MPH and the radar read 43MPH. Thought it was kind've weird but, it makes sense they design the speedometer to read faster.
Reply With Quote
  #14  
Old 04-08-2014, 08:18 PM
Dakster Dakster is offline
Posting Guru
 
Join Date: Dec 2013
Posts: 1,733
Dakster has a great reputation on FTE.Dakster has a great reputation on FTE.Dakster has a great reputation on FTE.Dakster has a great reputation on FTE.Dakster has a great reputation on FTE.Dakster has a great reputation on FTE.
My speedo is off, my odometer is on the money.
Reply With Quote
  #15  
Old 04-08-2014, 09:05 PM
Iowa Ford's Avatar
Iowa Ford Iowa Ford is offline
Elder User
 
Join Date: Mar 2013
Location: EC Iowa
Posts: 710
Iowa Ford is a splendid one to beholdIowa Ford is a splendid one to beholdIowa Ford is a splendid one to beholdIowa Ford is a splendid one to beholdIowa Ford is a splendid one to beholdIowa Ford is a splendid one to beholdIowa Ford is a splendid one to beholdIowa Ford is a splendid one to behold
Mine reads 2 mph fast too.
__________________
Tim."Honorary Canadian" Thanks Darren !
2012 F-250 XLT,CC,6.7,3.55ELD,FX4,Trailer tow, camper pkg, snow plow prep, Goose Neck Hitch, Ingot Silver, Work truck.
84 F-250 XL 6.9 IDI, 200k original stock
14-Escape 1.6 Eco Wife's car
07- Five Hundred Daughter's car
Reply With Quote
Old 04-08-2014, 09:05 PM
 
 
 
Reply

Go Back   Ford Truck Enthusiasts Forums > Diesel > 6.7L Power Stroke Diesel

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Speedo/toe MilllerTime Aerostar 2 02-03-2014 07:04 PM
Speedometer calibration, not an exact science mankypro Excursion - King of SUVs 5 11-19-2013 10:48 AM
Speedo Gear Issues (Yes, I searched) Social_Joe 1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks 1 04-04-2013 02:49 PM
Changing tire sizes dzwiss Brakes, Steering, Suspension, Tires, & Wheels 3 10-03-2012 02:38 PM
New tires and wheels dzwiss 6.7L Power Stroke Diesel 0 09-26-2012 08:00 PM



All times are GMT -5. The time now is 11:39 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup