Howdy Ranger fans. New member here.

[2009 ranger]

How do you figure your MPG if the speedo is off?

The best way I know is use the mile markers on a highway over at least ten miles, that can somewhat accurately give you an equation to use in figuring

In my area the roads are quite twisty and mile markers aren't always present, or consistent when they are. Only place they are accurate and consistent is on the interstate - and I try to stay off that unless I absolutely must be on it.

 

[Josh B]

I wouldn't really trust them any place else anyway. On a turnpike or interstate is the best place to really check one out.

On those roads there are two forces working that ensure accuracy. The Highway Department who pays for them, and is going to get every foot they paid for, and then the construction company, who is going to want paid for every foot they put into it
Even a ten mile check on one of those can tell about all you'd need to know

 

[Josh B]

Yeah, I'm a Ranger fan, grew up right outside Ft Worth. Some people at church would get free tickets to their home games and we'd go watch them pretty often. I don't know if you could get a free ticket any more tho

 

[2009 ranger]

I wouldn't really trust them any place else anyway. On a turnpike or interstate is the best place to really check one out.

On those roads there are two forces working that ensure accuracy. The Highway Department who pays for them, and is going to get every foot they paid for, and then the construction company, who is going to want paid for every foot they put into it
Even a ten mile check on one of those can tell about all you'd need to know

You are right, and I may need to do it again after new tires. But I pretty much know the problem. It's the solution I'm having trouble finding. The TruSpeed device worked perfectly on my '96 Ranger. One of Ford's "better ideas" seems to be making vehicles which can't be altered mechanically to suit their owner interests! Too many "bells and whistles" to disrupt if we try. It may be something I'll just have to live with.

 

[franklin2]

I looked into that but it looks to be way over my head. Not to mention, I don't have a laptop - or a smart phone, for that matter. My tire size is OEM. It's the gears I've changed.

No difference if it's tires or gears. The computer or the speedometer doesn't know the difference. Since that feature must be in the programming, see what the Ford dealer would charge to correct it.

 

[Josh B]

I looked into that but it looks to be way over my head. Not to mention, I don't have a laptop - or a smart phone, for that matter. My tire size is OEM. It's the gears I've changed.

I have a smart phone, it's equal to a tin can and a string, love it!

Maybe I'm just a numbers guy or something, but after switching tire sizes and finding (from Michelin and others who posted numbers to resolve questions) 7% was my number, so at 100 I was actually now doing 93, try that in a Ranger! But the point is, at 50 I would be doing 3.5% less. It's not something you wish to do every day but I have it to a point if my speed is being scanned I know where I'm at, with no worries about what it says on the dash

 

[2009 ranger]

No difference if it's tires or gears. The computer or the speedometer doesn't know the difference. Since that feature must be in the programming, see what the Ford dealer would charge to correct it.

Ford says they can't do it. I didn't ask if they meant THEY, my local dealer, can't do it, or it can't be done, period. Next time I'm there I think I'll ask that! I may be flogging a dead horse.

 

[2009 ranger]

I figured it out! The problem with using the SCT Tuner was that I was using the wrong tire Rev's per mile. The SCT tuner isn't really designed for my Ranger (more for a Mustang) but it does work - to a point! I only used it to change the gear ratio, and left everything else as is - specifically, I stuck with "stock tire rev's": Which I assumed the tuner, having recognized it was tuning a Ranger, would use the stock tire Rev's for the Ranger. Apparently it didn't. Tire size on a Mustang doesn't match what's on a Ranger! I changed the Rev's per mile to match the Ranger's tires and now I'm only around a mile per hour off at 60mph. The Odometer clicks to 1 mile after the truck rolls around 25-30 feet past the marker! But I need to make a test run on the interstate for more accurate readings. Now that I know what to do, I can make further adjustments if necessary But I can live with 1 mph off. I appreciate the help I received here. If nothing else, it got me thinking - and that's apparently what I failed to do when using the Tuner.

 

[Josh B]

That's awesome man! When I had to downgrade the 265 to 235 I went to tire sites such as Michelin and looked at their pages which calculated the numbers and then hit the turnpike and found it was accurate
I'm not bad at math so (my difference was 7%) so in 10 miles it would read as 9.3 (plus .7) = 10 which was right on.

It really isn't that hard to figure using simpler numbers and accurate mile markers

I once used the mile markers all the way across Arkansas to figure my gas mileage on an 80 Chevy LUV that had no working speedometer

 

[2009 ranger]

That's awesome man! When I had to downgrade the 265 to 235 I went to tire sites such as Michelin and looked at their pages which calculated the numbers and then hit the turnpike and found it was accurate
I'm not bad at math so (my difference was 7%) so in 10 miles it would read as 9.3 (plus .7) = 10 which was right on.

It really isn't that hard to figure using simpler numbers and accurate mile markers

I once used the mile markers all the way across Arkansas to figure my gas mileage on an 80 Chevy LUV that had no working speedometer

If I'd have known how simple it was to do I'd have had it done last January. I'll get out on the interstate and do some some miles to see just how close I got it. Sure glad I don't have to invest in bigger diameter tires.

 

[Josh B]

You can use internet sites like Michelin and Goodyear for tire size calculators in determining what to figure mathematically, otherwise I'd just recommend taking it out and going by the markers to know if it is telling you the facts or not

Once you "calibrate" the figures you'll always be on track

 

[2009 ranger]

Right on. Thanks.