Last post on Jul 23, 2010 at 7:36 PM
You are in the SUVs
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Ford Expedition, GMC Envoy, Chevrolet Suburban, Ford Escape, Honda CR-V, Nissan Pathfinder, Fuel Efficiency (MPG), SUV
May 21, 2009 (11:47 am)
I've been getting between 14.5 and 15.8 mostly city in 05 ford escape driving like an old lady. been super busy last week, driving faster, accelerating harder etc, and now 17.9mpg....no weight taken out, nothing new done to vehicle. any explanations??
#1062 of 1080 Re: MPG [twoplankr22]
May 21, 2009 (12:04 pm)
During warm-up you get poor mileage, so maybe the fact that you've been busy means you're driving it longer and more often when the engine is already warm. That helps.
Avoid short trips, and try to combine errands so the engine is already warm when you start.
#1063 of 1080 Re: MPG [twoplankr22]
May 22, 2009 (5:15 am)
Lots of things contribute to mileage and perceived mileage.
For instance, the position of the car when fueling. Generally if it is leaning away from the filler tube, the tank will accept more fuel, same if sitting with the front lower than the rear. So for more accurate calculations, always use the same pump with the car sitting in the same position.
Set the nozzle "Switch" at the slowest setting and let it run until it clicks off, and STOP! EVERY TIME.
Just using some numbers for the sake of example.
We drive 225 miles and it takes 15 gallons to fill the tank on level ground.=15 mpg. If the car is leaning away from the pump or the front is down hill, the tank may take 16-17 gallons. = 13-14 mpg. Since it has taken on 1-2 extra gallons of gas, the next 225 miles might take only 13-14 gallons if filled on level ground again.= 16-17 mpg.
Throttle position can also make a difference. I've found that with our 03 pilot I seem to get better mileage when using enough throttle to allow transmission shifts, without lifting my foot, at 2200 rather that 2000 rpm. However at 2500 the mileage is worse than letting it shift at 2000. Engines have sweet spots that are the most economical. Delicate balance between engine economics and transmission shifting, which goes back to engine economics. Seems to be an ever ending circle.
And as ateixeira said above, you may have been doing more driving with a warm engine.
My work commute is 6-7 miles depending to the route I take. With air temperature at 40 degrees the cold started engine will deliver 16-17 mpg. With engine at operating temps, more in the 21 mpg range. Shorter drives reflect lot bigger differences.
A Scan Gauge II is a useful tool as it can show all types of functions. Most useful to me are instant real world mileage and trip mile which can be reset any time. Even resetting it for different trips, it will still keep track of todays mileage as well as previous day and tank. Wonderful and useful toy!
Short version: Don't get terribly excited about a particularly good of particularly bad tank of gas. There are too many variables.
#1064 of 1080 Expedition, MPG
Jun 02, 2009 (1:47 pm)
I just drove my 2002 Expedition from Jacksonville, Fl to Panama City Beach. At 60-65 mph, I got 24 MPG. However my in-town driving nets only 14-16 MPG. Would disconnecting the battery to reset the computer be of any value?
#1065 of 1080 Re: Expedition, MPG [dasdal]
Jun 04, 2009 (8:45 am)
That sounds about right actually.
Wasn't the EPA 14/18, something like that? That was even before they revised those figures down in 2008 or so.
Your highway mileage is actually better than I expect.
#1066 of 1080 Re: Expedition, MPG [dasdal]
Jun 04, 2009 (9:36 am)
Would disconnecting the battery to reset the computer be of any value?
Yup, with the battery disconnected, it will prevent you from driving it. Which in turn will increase the gas mileage infinitely.
The longer you keep the battery disconnected, the better overall fuel economy you will get.
#1067 of 1080 Re: Expedition, MPG [blueiedgod]
Jun 04, 2009 (9:38 am)
You'll save fuel but be ready to replace your shoes more often.
#1068 of 1080 Re: Expedition, MPG [dasdal]
by steve_ HOST
Jun 04, 2009 (11:13 am)
I think the theory is that if you reset the engine computer by disconnecting the battery, the car components will have to relearn your driving style. So if you take it real easy after the reset, the SUV will learn to sip fuel, go easy on the shifting, etc.
I don't think it works like that in the real world though. The computers may have to relearn, but they are always compensating depending on what signals the various sensors are sending them.
It's a cheap experiment to try (assuming that you don't lose a radio antitheft or other security code when you disconnect the battery and have to pay a dealer to reset it).
#1069 of 1080 Re: Expedition, MPG [steve_]
Jun 04, 2009 (11:19 am)
In my experience they start rich and then lean the fuel mix out as you go. So odds are the first tank will have even lower mileage than he's getting now.
Longer-term it may have small gains, but I bet checking the tire pressure more often works out just as well.
#1070 of 1080 Re: Expedition, MPG [ateixeira]
by steve_ HOST
Jun 04, 2009 (11:34 am)
I threw away a seat in my minivan when we first got it a decade ago. I bet that's saved me a nice hunk of gas over the years.
Yeah, check the tires, toss out the extra junk stashed in the back of the SUV, anticipate the red lights. That simple stuff goes a long way.