20-22 MPG

[OneTakeJake]

Just curious about everyone’s MPG. Before I put on my K02’s 245 I was getting around 26-28 MPG. With the bigger tires I put on it dropped significantly to 21 and if I’m luck 22 MPG. That is a big decrease or does that seem right?

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[tburner]

Just curious about everyone’s MPG. Before I put on my K02’s 245 I was getting around 26-28 MPG. With the bigger tires I put on it dropped significantly to 21 and if I’m luck 22 MPG. That is a big decrease or does that seem right?

Did you correct your tire circumference using FORScan? If you put larger tires on but your BS still thinks you have the OEM tires, your odometer will think you're traveling less distance, your indicated MPGs will drop, and your indicated speed will be less than your actual speed.

 

[OneTakeJake]

Did you correct your tire circumference using FORScan? If you put larger tires on but your BS still thinks you have the OEM tires, your odometer will think you're traveling less distance, your MPGs will drop, and your indicated speed will be less than your actual speed.

I did not do that, how would I go about getting that done?

 

[tburner]

I did not do that, how would I go about getting that done?

Download FORScan, download an extended license, buy an OBDII cable (this one or this one), then follow these instructions.

It is strongly recommended you download backups of your as built configurations for each module. I did a quick search and this video appears to explain how to do it. I didn't actually watch it. Apologies if it sucks.

After you update your circumference, use a GPS app on your phone or something to compare your actual speed to your indicated speed. That'll help you dial in your actual circumference (calculated circumference will probably be about 2% - 3% off).

[current circumference] × [GPS speed] ÷ [indicated speed] = [corrected circumference]

Or if you're ever in the DFW Texas area I can help you out.

 

[V8 Yankee]

Just curious about everyone’s MPG. Before I put on my K02’s 245 I was getting around 26-28 MPG. With the bigger tires I put on it dropped significantly to 21 and if I’m luck 22 MPG. That is a big decrease or does that seem right?

If you didn't have your speedo recalibrated then those numbers are not accurate. Any Ford Dealer can recalibrate the ECU, it's a programming change, no mechanical change. They'll need the diameter of your new tires, fully inflated to your normal tire pressure. Five minute procedure. Afterwards fill the tank, reset the mpg and that's it. Easy peesy.

 

[tburner]

Any Ford Dealer can recalibrate the ECU...

Good suggestion, though I think it'll have to be a dealership that offers FORScan services.

When I first did mine, FORScan couldn't relearn the PCM. I took it to the dealer and they told me Ford doesn't let dealerships adjust tire sizes anymore. They said they also had to use FORScan, but since it couldn't do the relearn yet they were using a Rough Country module.

The latest version of FORScan can relearn the PCM now so that shouldn't be a problem anymore.

 

[Ksnau]

first I apologize my posts are always really long. Yeah the computer will show less miles per gallon because you have taller tires so you're actually going a little bit further for each rotation of the wheel and if the computer doesn't know that it can't account for that so it thinks you're going less distance but if you do the math it probably wouldn't even equate to one MPG I will tell you on my 2014 Ford escape when I did that I believe the same size as you I did lose two MPG but I also never reset my ECU for tire size. also I went from averaging 26 to it was really like 23.6 instead of 24 so you could say two to three MPG loss also though those MPGs that your car calculates are rarely exactly right usually they can be off by one to two MPG if not more so what you really need to do is fill up your tank if possible use Google maps or something to track exactly how many miles you drive do that for like 2 days fill up your tank again and see how many gallons goes in there and divide that by the number of miles you drive and that's your real MPG and I pretty much guarantee it's going to be different than what the car's computer says by at least a little bit but to me that does seem like a more drastic change than would be normal if you have the two liter engine you should only have to feather the gas pedal to go anywhere if you doing more than that you're using more gas than you should need to unless you're like in the mountains or something and even then you probably shouldn't if you have the 1.5 I couldn't say I've never had that engine maybe you do have to gas it more because you have bigger taller tires and they're a little bit heavier so it takes more oomf to get going but I would try to just drive a little more conservative even with the three cylinder you shouldn't have to press the gas pedal hardly at all to get going to a decent speed and you'd be surprised the difference in miles per gallon that you get also I rarely go over 75 mph especially with the bronco which has a more flat front than my escape did that air resistance really builds up over 7075 and you have to press the gas more to get going faster and it can really affect your MPG trying to go 80 or 85 versus 70 or 75. I usually hate eco mode though I usually never use them and I still get pretty good gas mileage but you could also try the Eco mode too.

 

[RiotfunK]

You added 20lbs a tire. That’s a lot of added rotational mass. What did you expect on a small turbo vehicle

 

[Bluebaru]

Has anyone had a Dealer recalibrate the speedo with FORScan yet and if so, how much did it cost?

 

[V8 Yankee]

If you didn't have your speedo recalibrated then those numbers are not accurate. Any Ford Dealer can recalibrate the ECU, it's a programming change, no mechanical change. They'll need the diameter of your new tires, fully inflated to your normal tire pressure. Five minute procedure. Afterwards fill the tank, reset the mpg and that's it. Easy peesy.

To add to my calibration comment. Since I wrote that I've read some Ford dealers tread lightly, pardon the pun when calibrating for different sized tires other than stock. Ford has had legal issues on tire related crashes and roll overs so your local dealer may not calibrate your speedo, aka ECU.

 

[BoxerBronco]

Has anyone had a Dealer recalibrate the speedo with FORScan yet and if so, how much did it cost?

A dealer will not use ForScan…

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