SERIOUS Gas Mileage Problems - 200miles out of a Tank!
10-06-2011, 03:47 PM
#1
2nd Gear Member
Thread Starter
Join Date: Mar 2010
Location: Toronto, Ontario
Posts: 417
SERIOUS Gas Mileage Problems - 200miles out of a Tank!
Hey guys,
As the title says...
I own a 2010 Mustang, V6 Coupe.
Yes, I know not to make gas mileage a priority when buying a Mustang but this is starting to become unreasonable. I'm getting less than 200 miles out of a tank of gas and can't seem to figure out why.
I've been running a pretty strict spreadsheet on my gas mileage. So far, it has been nothing but bad news.
Currently at 50,000km (Canadian) driven. The warranty expires at 60,000km, so I need to get on the ball with this issue asap.
I've already taken it to the dealership (but might have to take it to another one)they hooked up the laptop to it and took it for a drive for about a half hour / approx 50km. Said all the reads look completely normal (street and highway) and that all the MPG/ L/100km looks normal. Sure the computer says everything is ok, but my tank of gas says different at the end of the day.
I'm thinking that I need to take it to another dealership, maybe we have a Ford Customer Service Rep pipe up and help out here on the forums.
Things I've checked so far:
-Tire pressure, been running between 32 - 35 PSI regularly on 20 inch wheels and tires.
-No unnecessary weight in the trunk/backseats (I don't weigh 300 pounds)
-Regular Oil and Filter Changes, Royal Purple 5-W30 and K&N Filters
-Air Filters has been changed twice now
-Mods: Dual Exhausts w/ X-Pipe, the end, nothing else.
-No leaks or anything for the sort.
-Fill up regularly at Shell, regular gas, not premium, did premium for 2 months, didn't make a difference in gas mileage, went back to regular.
-Mixed City + Highway driving - 50/50
-Don't have a lead foot. I use cruise control as often as possible to help out on gas mileage.
-I don't idle.
From what I've been told, I won't have to replace the Spark Plugs anytime soon (running OEMs) but am willing to do so if recommended.
Is there anything I need to replace or look at? Any other filters, cans or anything that need to be replaced.
You folks have been my source of information and I'm really looking for help, at this rate it feels like I'm making 2x car payments.
Really don't want to have to resort to selling the car,
Any help would be appreciated!
Thanks
As the title says...
I own a 2010 Mustang, V6 Coupe.
Yes, I know not to make gas mileage a priority when buying a Mustang but this is starting to become unreasonable. I'm getting less than 200 miles out of a tank of gas and can't seem to figure out why.
I've been running a pretty strict spreadsheet on my gas mileage. So far, it has been nothing but bad news.
Currently at 50,000km (Canadian) driven. The warranty expires at 60,000km, so I need to get on the ball with this issue asap.
I've already taken it to the dealership (but might have to take it to another one)they hooked up the laptop to it and took it for a drive for about a half hour / approx 50km. Said all the reads look completely normal (street and highway) and that all the MPG/ L/100km looks normal. Sure the computer says everything is ok, but my tank of gas says different at the end of the day.
I'm thinking that I need to take it to another dealership, maybe we have a Ford Customer Service Rep pipe up and help out here on the forums.
Things I've checked so far:
-Tire pressure, been running between 32 - 35 PSI regularly on 20 inch wheels and tires.
-No unnecessary weight in the trunk/backseats (I don't weigh 300 pounds)
-Regular Oil and Filter Changes, Royal Purple 5-W30 and K&N Filters
-Air Filters has been changed twice now
-Mods: Dual Exhausts w/ X-Pipe, the end, nothing else.
-No leaks or anything for the sort.
-Fill up regularly at Shell, regular gas, not premium, did premium for 2 months, didn't make a difference in gas mileage, went back to regular.
-Mixed City + Highway driving - 50/50
-Don't have a lead foot. I use cruise control as often as possible to help out on gas mileage.
-I don't idle.
From what I've been told, I won't have to replace the Spark Plugs anytime soon (running OEMs) but am willing to do so if recommended.
Is there anything I need to replace or look at? Any other filters, cans or anything that need to be replaced.
You folks have been my source of information and I'm really looking for help, at this rate it feels like I'm making 2x car payments.
Really don't want to have to resort to selling the car,
Any help would be appreciated!
Thanks
10-06-2011, 04:39 PM
#3
2nd Gear Member
Thread Starter
Join Date: Mar 2010
Location: Toronto, Ontario
Posts: 417
Seems to always have been a problem. Odometer seems to be correct. Again, I could very well be wrong. Calibration was not changed to account for the 20" wheels. Would this have affected the gas mileage? Thanks for your help.
10-06-2011, 04:51 PM
#4
4th Gear Member
Join Date: Nov 2008
Location: California
Posts: 1,495
It would affect what you think the gas mileage is. If you're using the odometer to tell you how many miles you traveled, and it wasn't calibrated for the 20" wheels, you could be getting an erroneous mileage reading. Maybe compare the odometer to a GPS device.
10-06-2011, 05:02 PM
#6
4th Gear Member
Join Date: Jul 2010
Location: Ohio
Posts: 1,498
Bigger rims and tires will decrease it slightly as that adds higher rolling resistance. But not drastically. And yes, if your computer isn't calibrated for your size tires, the odometer reading will be off. Same if you were to go change your gear ratios.
I track my fuel pretty extensively as well with www.fuelly.com and my vehicles gas mpg ranges from 9.7 mpg in my 06 GT to 20.5 mpg in my 04 V6 and 27 mpg in my 00 Sable. It's a pretty cool website, but it does all go based off your odometer.
A tuner like a SCT X3 could correct the odometer reading by compensating for the 20 rims.
I track my fuel pretty extensively as well with www.fuelly.com and my vehicles gas mpg ranges from 9.7 mpg in my 06 GT to 20.5 mpg in my 04 V6 and 27 mpg in my 00 Sable. It's a pretty cool website, but it does all go based off your odometer.
A tuner like a SCT X3 could correct the odometer reading by compensating for the 20 rims.
10-06-2011, 05:14 PM
#7
1st Gear Member
Join Date: Oct 2007
Posts: 117
I used to get horrible mileage until I re-did my gears and changed to a 1 piece DS.
MPG before changes = 10.
MPG after = 14.5
not sure if it was just the DS or a combination of gears and DS.
The gears were 3.73 that were noisy, changed to FRPP 3.73.
Good luck
MPG before changes = 10.
MPG after = 14.5
not sure if it was just the DS or a combination of gears and DS.
The gears were 3.73 that were noisy, changed to FRPP 3.73.
Good luck
10-06-2011, 05:24 PM
#8
4th Gear Member
Join Date: Jul 2010
Location: Ohio
Posts: 1,498
How did you calculate that? Just curious as that's a HUGE mpg change. The one piece driveshaft will help some as it's reducing rotational mass weight but the gear change wouldn't have affected unless you were from a 3.73 to 3.27 or something. That would be a big enough change to see the difference.
10-06-2011, 05:34 PM
#9
2nd Gear Member
Join Date: Aug 2010
Location: texas
Posts: 213
i think youve found your problem.
heres an example.
lets give a rough example. (im leaving out alot of the details, tire size and these are not exact or accurate numbers BUT they will give you an idea of how it works and whats happening).
lets pretend that one rotation of a 17 inch wheel takes the car this far
----------
lets pretend one rotation of a 20 inch wheel takes the car this far
------------------
the car still thinks it has 17 inch wheels on so every time it rotates once the car assumes you went.
----------
But in fact you have 20 inch wheels so one rotation actually took the car
-----------------
but it doesn't know this so it reported that you went a shorter distance then you really did. so basically your car thinks your not going as far as you really are. so when you use your odometer reading to calc gas mileage you end up with a crappy number. however you actually went further and your real mileage is fine.
heres an example.
lets give a rough example. (im leaving out alot of the details, tire size and these are not exact or accurate numbers BUT they will give you an idea of how it works and whats happening).
lets pretend that one rotation of a 17 inch wheel takes the car this far
----------
lets pretend one rotation of a 20 inch wheel takes the car this far
------------------
the car still thinks it has 17 inch wheels on so every time it rotates once the car assumes you went.
----------
But in fact you have 20 inch wheels so one rotation actually took the car
-----------------
but it doesn't know this so it reported that you went a shorter distance then you really did. so basically your car thinks your not going as far as you really are. so when you use your odometer reading to calc gas mileage you end up with a crappy number. however you actually went further and your real mileage is fine.
10-06-2011, 05:40 PM
#10
2nd Gear Member
Thread Starter
Join Date: Mar 2010
Location: Toronto, Ontario
Posts: 417
i think youve found your problem.
heres an example.
lets give a rough example. (im leaving out alot of the details, tire size and these are not exact or accurate numbers BUT they will give you an idea of how it works and whats happening).
lets pretend that one rotation of a 17 inch wheel takes the car this far
----------
lets pretend one rotation of a 20 inch wheel takes the car this far
------------------
the car still thinks it has 17 inch wheels on so every time it rotates once the car assumes you went.
----------
But in fact you have 20 inch wheels so one rotation actually took the car
-----------------
but it doesn't know this so it reported that you went a shorter distance then you really did. so basically your car thinks your not going as far as you really are. so when you use your odometer reading to calc gas mileage you end up with a crappy number. however you actually went further and your real mileage is fine.
heres an example.
lets give a rough example. (im leaving out alot of the details, tire size and these are not exact or accurate numbers BUT they will give you an idea of how it works and whats happening).
lets pretend that one rotation of a 17 inch wheel takes the car this far
----------
lets pretend one rotation of a 20 inch wheel takes the car this far
------------------
the car still thinks it has 17 inch wheels on so every time it rotates once the car assumes you went.
----------
But in fact you have 20 inch wheels so one rotation actually took the car
-----------------
but it doesn't know this so it reported that you went a shorter distance then you really did. so basically your car thinks your not going as far as you really are. so when you use your odometer reading to calc gas mileage you end up with a crappy number. however you actually went further and your real mileage is fine.
So I should go get it re-calibrated, then test again?
Where does one go to get it re-calibrated? Stealership?
How much am I looking at spending on getting this done?