MPG perplexed
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MPG perplexed
I have a 2003 v10 Ex. I occasionally drive it between Tucson and Phoenix at 65 miles per hour and get average about 10.5 MPG. Recently, I loaded the entire family in it, 6 people, an English mastiff, luggage, and a giant Yakima roof box, and headed to Colorado. Between Durango and Colorado Springs i drove it hard, really hard. I kept it around 70 the whole way including going up and over wolf creek pass and made several pedal to the floor passes around super slow Coloradans. I averaged 13 mpg!?!? Did it again going the other way and got the same results. Coming back to Arizona I dropped back down to just under 11 mpg. Anyone have an explanation for this??
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From: Media PA
To me the 13 MPG seems closer to what the normal mileage should be in either scenario, I'm perplexed by the typical 10.5 MPG on that 100-ish mile regular trip at 65 MPH. I do very little unloaded driving in our EX as it is our dedicated tow rig so most unloaded miles are local to our destinations and sightseeing short trips. But last August we took a load of stuff out to Columbus OH from our home near Philly and on the way home with 3 adults onboard I set the cruise control at 65 MPH for the entire 450 mile all highway trip home and got 14.5 MPG using the AC for about half the trip. Our EX is lifted 4" with 35"X12.8" tires with Banks headers and running 5Star's 89 Octane Performance tune.
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To me the 13 MPG seems closer to what the normal mileage should be in either scenario, I'm perplexed by the typical 10.5 MPG on that 100-ish mile regular trip at 65 MPH. I do very little unloaded driving in our EX as it is our dedicated tow rig so most unloaded miles are local to our destinations and sightseeing short trips. But last August we took a load of stuff out to Columbus OH from our home near Philly and on the way home with 3 adults onboard I set the cruise control at 65 MPH for the entire 450 mile all highway trip home and got 14.5 MPG using the AC for about half the trip. Our EX is lifted 4" with 35"X12.8" tires with Banks headers and running 5Star's 89 Octane Performance tune.
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From: Media PA
I surprised by the 10.5 too. I expected 12-14 when I bought it. I’ve had it 2 years and it’s always been steady at 10.5 hiway driving until this trip. I don’t understand why it’s so low usually and why it jumped up when it should have gone down I would really like to understand how to get it up to 13 all the time
What size tires and which gear ratio does your EX have?
Ever verified speedometer accuracy vs a GPS?
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Laughing Gas
Joined: Jul 2018
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From: Prescott, AZ
Regardless of the absolute fuel economy, there would still be a significant relative difference provided the same calculation method is being used in both examples. Having NASA-calculated fuel burns aren't necessary - it's enough to know that there is a broad swing between Tucson-Phoenix and vaction-type driving.
My guess is the Tucson-Phoenix trip involves less steady-state driving (that corridor is a freakin' disaster every mile of it now) than a vacation drive. Temperature may be a factor as well, but Colorado can get pretty hot in the summer also...
My guess is the Tucson-Phoenix trip involves less steady-state driving (that corridor is a freakin' disaster every mile of it now) than a vacation drive. Temperature may be a factor as well, but Colorado can get pretty hot in the summer also...
Fleet Mechanic
Joined: Oct 2010
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From: South Eastern Michigan
I feel that certain RPM ranges coupled with weight and wind resistance play a huge part of mileage in a vehicle this size and shape. For instance, my '06 P71 gets 21 no matter how I drive it. I have a long drive to work and its usually in the 80 MPH range. Its a low profile shape with a big V8 so very little effort to get it through the wind. My EX relaxes around 70-75 MPH, even with a trailer. 65 it seems to be working harder to maintain speed and 80 is to much rpm. I think you'll find that if you get it above 70, you'll get better mileage. And yes, I've paid attention to this sort of thing the past few years. Long boring drives with and without a trailer allow me to ponder such things.
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From: Media PA
I agree that running faster, even with the aero drag increases, can net better mileage up to a point of course. I could see a 3.73 geared gasser EX falling into this catagory, especially with taller than stock tire's. The V-10 likes to rev and is more efficient at higher revs (to a point...) and the 31.6" tire and 3.73 gear isn't optimal at 65 MPH, With 4.30s I think it might actually do better at 65 MPH, like my 14.5 MPG trip I mentioned above.
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From: Houston, Texas
This was actually proven a few years ago. The V10 seemed happy around 70-75+, some folks were running about 80 and instead drinking down gas, it sipped it.
When some folks did 65 some got better mpg, some got worse
When some folks did 65 some got better mpg, some got worse
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the mpg sound bad , I have v10 3.73 gear at 62 issh 2,000 rpm I get about 16 highway and 10 intown. towing my travel trailer I get about 10. Hand calculated . I've gone from Miami fl to Tennessee Gatlinburg same mpg. Been to new jersey towing travel trailer even in mountain still around 10