silvrsvt Posted July 29, 2013 Share Posted July 29, 2013 Not exactly the most scientific testing in the world, but had me wondering after my dad mentioned it to me when they came down this past weekend. Example 1: My 2013 SHO has about 6700 miles on it and I've been back and forth to NJ from MD (about 135 miles one way) quite a few times with the cruse control set at 75-80 MPH. I'll get out of the gas station right before getting onto I-95 and reset my MPG reading on MFT when I hit the highway. I know when you do this at first you get an inflated number then it settles down into the proper MPG range. Well when I do this in the SHO, it reads about 27 MPG (a bit higher then the MPG ratings) then for the next 75 miles, it keeps dropping and dropping till it settles out at anywhere from 20-21 MPG, which is quite a bit lower then EPA ratings of 25 MPG, which I've only been able once to hit with the car. I get about the same MPG ratings for the car driving around town. I releaze that the Ecoboost engines are throttle sensitive (if I gun it I can kill the MPG by at least 2)...but I can't figure out why it keeps dropping MPG with the cruise enabled. On two non-ecoboost engines making the same trip, a 4.6L V8 with nearly 120K miles and a 3.0L V6/AWD with 95K miles on it, doing the same trip, they will start reporting higher mileage, then only maybe drop a MPG or two and not go lower till you start doing around town driving and getting their MPG ratings or even better doing the same drive. Example 2: My parents have a '13 Escape Ti with a FWD 2L Ecoboost engine in it. They drove down to my place, and more or less did the same thing I did...got gas, reset the MPG counter and drove down doing 70 MPH using the cruise control. My dad reported getting about 29 MPG at first, then by the time he got to my place, he was only avg about 24 MPG. They didn't hit any major traffic or anything, nor where they using the AC, which my dad says has a major impact on his MPG's with the Escape (and I get most other 4 cyc engines)...he also made it a point to drive very conservatively to get the most out of his MPGs also. Has anyone else ran into a issue like this with their Ecoboost engine? I know the MPG counter in the dash isn't the most accurate thing in the world, but getting 20-25% less then what the EPA MPG estimates is a bit disconcerting. Quote Link to comment Share on other sites More sharing options...
akirby Posted July 29, 2013 Share Posted July 29, 2013 Too many factors here. I've noticed that I get several mpg better going South on one local interstate and several mpg worse coming back home - I presume due to an elevation change. You should check both directions and average the result to make sure that's not a factor. What I've found with the EB engines is they are very sensitive to throttle input especially when going uphill. With the cruise on it will use throttle to keep the desired speed and that wastes fuel especially in EB engines. It's better to feather the throttle and let the speed drop a little going uphill. Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted July 29, 2013 Author Share Posted July 29, 2013 Too many factors here. I've noticed that I get several mpg better going South on one local interstate and several mpg worse coming back home - I presume due to an elevation change. You should check both directions and average the result to make sure that's not a factor. its not, I'm usually fueling up on the way home and I'm getting the same #'s....as for too many factors...I understand traffic etc...but I've done the drive at 20 (counting going up and down) or so times since April when I got the car and I've had the same experience each trip. Quote Link to comment Share on other sites More sharing options...
fordmantpw Posted July 29, 2013 Share Posted July 29, 2013 Has anyone else ran into a issue like this with their Ecoboost engine? I know the MPG counter in the dash isn't the most accurate thing in the world, but getting 20-25% less then what the EPA MPG estimates is a bit disconcerting. I can't help with the numbers dropping the length of the trip (unless it is constant uphill, or lots of hills like akirby mentioned), but you aren't exactly picking the best speeds to meet the EPA ratings. Try driving 60-65...I bet you'll get several MPG better. Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted July 29, 2013 Author Share Posted July 29, 2013 I can't help with the numbers dropping the length of the trip (unless it is constant uphill, or lots of hills like akirby mentioned), but you aren't exactly picking the best speeds to meet the EPA ratings. Try driving 60-65...I bet you'll get several MPG better. I know that, but do keep in mind that your avg speed is often lower then what you locked into the cruise control..and on different engines didn't have such a big drop doing the same drive in similar conditions. I've beat EPA ratings (going by my trip computer) in my Mustang going up and down the same route and my Fiancee reported getting nearly 30MPG out of her Escape driving to Washington DC doing the same thing driving the same route. I just find it weird that its very hard to hit the numbers the EPA has put out for the Ecoboost numbers highway (which should be the easiest to do with using cruse control and steady state driving) vs a non DI/Turbo car. Quote Link to comment Share on other sites More sharing options...
Edstock Posted July 29, 2013 Share Posted July 29, 2013 with the cruse control set at 75-80 MPH. but getting 20-25% less then what the EPA MPG estimates is a bit disconcerting. 75-80 mph, and you're bitching that it doesn't meet EPA figures? Quote Link to comment Share on other sites More sharing options...
akirby Posted July 29, 2013 Share Posted July 29, 2013 If you have the instant mpg display you'd see that fuel consumption isn't exactly linear with the throttle. It stays really low up to a point them goes way up. Or looking at it inversely, your mpg stays relatively high up to around 2000 RPM, then falls off a cliff at a certain point. e.g. If I'm cruising along on flat ground at 60 mph I might be getting 34 mpg. As soon as I hit a hill and have to give it just a little bit of throttle to maintain close to 60 mph my mileage drops to 22. Quote Link to comment Share on other sites More sharing options...
akirby Posted July 29, 2013 Share Posted July 29, 2013 75-80 mph, and you're bitching that it doesn't meet EPA figures? The EPA highway test averages 48 mph. Quote Link to comment Share on other sites More sharing options...
351cid Posted July 29, 2013 Share Posted July 29, 2013 With our 2L Fusion SE, we average 31-33 mpg on the trip to Asheville, NC. My wife's dad has been sick, so she's made 6 trips since we bought the car. She normally sets the cruise on 70 and rolls. Western NC is mountainous and the piedmont area is rolling hills. Quote Link to comment Share on other sites More sharing options...
RangerM Posted July 29, 2013 Share Posted July 29, 2013 Just my observation on the various cars I've rented, it seems common the MPGs start to drop precipitously beyond about 70. (it varies by make/model) I don't know if it applies to EB or not, but a small engine isn't going to have the torque at lower RPMs, requiring an upshift more often going uphill. I can pretty much put my Ranger in 5th and forget it (on cruise) so long as I'm running just above 2K rpms. (at/near peak torque) Quote Link to comment Share on other sites More sharing options...
fordmantpw Posted July 29, 2013 Share Posted July 29, 2013 I know that, but do keep in mind that your avg speed is often lower then what you locked into the cruise control..and on different engines didn't have such a big drop doing the same drive in similar conditions. I've beat EPA ratings (going by my trip computer) in my Mustang going up and down the same route and my Fiancee reported getting nearly 30MPG out of her Escape driving to Washington DC doing the same thing driving the same route. I just find it weird that its very hard to hit the numbers the EPA has put out for the Ecoboost numbers highway (which should be the easiest to do with using cruse control and steady state driving) vs a non DI/Turbo car. In both our Flex and my F250, I can get better fuel economy when I leave the cruise off. As long as I don't feel I have to keep the same speed going up hills as I do on flat ground, I can keep my foot out of it, stay in the highest gear, slow down a few MPH going up the hill, then pick it back up going down the hill. Things are exaggerated even more when I have my fifth wheel behind me, to the point that I can get 1-1.5 MPG BETTER towing the fiver if I leave the cruise off. Keep in mind, that's from a base of 10, so 1-1.5 is a drastic increase! Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted July 29, 2013 Author Share Posted July 29, 2013 (edited) In both our Flex and my F250, I can get better fuel economy when I leave the cruise off. As long as I don't feel I have to keep the same speed going up hills as I do on flat ground, I can keep my foot out of it, stay in the highest gear, slow down a few MPH going up the hill, then pick it back up going down the hill. Things are exaggerated even more when I have my fifth wheel behind me, to the point that I can get 1-1.5 MPG BETTER towing the fiver if I leave the cruise off. Keep in mind, that's from a base of 10, so 1-1.5 is a drastic increase! That I understand...your going up hill and your car or truck is going to want to keep its speed no matter what with the cruse on, but I'm talking mostly flat areas with little increases in elevation...from what I understand the steepest grade your going to find on the international highway system is 6%... Edited July 29, 2013 by silvrsvt Quote Link to comment Share on other sites More sharing options...
351cid Posted July 29, 2013 Share Posted July 29, 2013 That I understand...your going up hill and your car or truck is going to want to keep its speed no matter what with the cruse on, but I'm talking mostly flat areas with little increases in elevation...from what I understand the steepest grade your going to find on the international highway system is 6%... I've seen several interstates with 7% grades. Quote Link to comment Share on other sites More sharing options...
MKII Posted July 29, 2013 Share Posted July 29, 2013 Compare your averages by driving the same trip without using cruise control. I find using cruise control does not result in good mpg, when compared to not using cruise control. Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted July 29, 2013 Author Share Posted July 29, 2013 I've seen several interstates with 7% grades. If your in mountains! I'm talking Eastern seaboard...flat as a board Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted July 29, 2013 Author Share Posted July 29, 2013 I find using cruise control does not result in good mpg, when compared to not using cruise control. How is that even possible? No one has a calibrated foot...and its impossible to keep the car at the same speed limit all the time just using your foot. Your going to wander a couple MPH in either direction vs the car's computer keeping at a set speed. I can see it not being as effective in hilly areas...but where I'm driving there isn't any major inclines or declines. http://www.edmunds.com/fuel-economy/we-test-the-tips.html#test3 Quote Link to comment Share on other sites More sharing options...
Extreme4x4 Posted July 30, 2013 Share Posted July 30, 2013 My 2013 Explorer Sport also has the EB 3.5L. We have close to 12,000 miles on it now, and have made some observations on fuel economy. Using cruise control will net lower mileage than your own foot. We notice this in our '08 F250 V10 also. The programming of the cruise is very aggressive, and it will use a much stronger throttle input than we will, to maintain speed. As for mileage, or Sport is getting EPA or better mileage. This is on a 240 mile round trip that is done once weekly. We are going from 5100ft to 1800ft, back up to 6900ft and back down to 1100ft. This is with speed limits of 65 (we do 69-72), and a short distance of 75 (we do 79). This also includes a short distance of stop and go (stop signs and a few lights). Our average for this trip is 22-23mpg, depending on how we drive. This is mountainous country with curves. This is with wind. This is with extremely hot temps (up to 115), and extremely cold temps (winter down to 5-10, and snow and ice). This is not babying it. There will also be the occasional "fun." The Sport is rated at 16mpg city and 22mpg highway. One trip was done as an experiment with never going over the speed limit. Upon pulling into home, the mpg was 25.1mpg. These vehicles have a lot of frontal area. While your SHO isn't as high as our Sport, it still has very large frontal area. This is where your 75-80mph comes into play. It is killing your mpg. Try the same trip running 65mph the entire way, and be amazed at what your mileage will be. Also, with a lot of frontal area, wind will be huge in affecting you. We are thrilled with the mileage of our Sport. If we drove at 75-80 all the time, I have no doubt that we would be averaging 20mpg. Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted July 30, 2013 Share Posted July 30, 2013 I was thinking about this earlier, and came up with something along the lines of Gloria's remarks--acceleration to resume speed. I'm guessing your East Coast interstates don't much resemble ours: http://rachelkossman.files.wordpress.com/2010/05/img_0040.jpg Quote Link to comment Share on other sites More sharing options...
mustang_sallad Posted July 30, 2013 Share Posted July 30, 2013 In the interest of science, I think it's time for you to do a run at 60mph. You may decide that your time is worth more than what you'd be saving on gas, but at least you'd know. And knowing is half the battle. Quote Link to comment Share on other sites More sharing options...
fgll Posted July 30, 2013 Share Posted July 30, 2013 I used to have a 2012 Focus HB SEL DCT and I found the same fuel economy situation when using the cruise control. I also noticed that the car maintained the set speed up hill but also down hill (It felt like it applied a little braking by itself) no matter what kind of slope it was going through. I believe that this may affect the fuel economy a little since the car is not coasting freely. When the cruise control is not active and I did have full control of the car, it went downhill a little faster and coasted freely. Does this sounds logic to you all ??? Quote Link to comment Share on other sites More sharing options...
chevys Posted July 30, 2013 Share Posted July 30, 2013 How is that even possible? No one has a calibrated foot...and its impossible to keep the car at the same speed limit all the time just using your foot. Your going to wander a couple MPH in either direction vs the car's computer keeping at a set speed. I can see it not being as effective in hilly areas...but where I'm driving there isn't any major inclines or declines. http://www.edmunds.com/fuel-economy/we-test-the-tips.html#test3 Cruise control is a convenience item and nothing more. Its actually a gas mileage killer in hilly areas. It waits to speed up when its too late using way more throttle. Without cruise, you can speed up on flat ground before a big hill and back off the throttle as you climb and its much more efficient. My guess is that its worse on boosted engines vs the NA counterparts. Quote Link to comment Share on other sites More sharing options...
2005Explorer Posted July 31, 2013 Share Posted July 31, 2013 I was thinking about this earlier, and came up with something along the lines of Gloria's remarks--acceleration to resume speed. I'm guessing your East Coast interstates don't much resemble ours: http://rachelkossman.files.wordpress.com/2010/05/img_0040.jpg I can't imagine driving from Spearfish to Sioux Falls at any speed less then 75-80 with the cruise set. MPG be damned! Quote Link to comment Share on other sites More sharing options...
akirby Posted July 31, 2013 Share Posted July 31, 2013 I used to have a 2012 Focus HB SEL DCT and I found the same fuel economy situation when using the cruise control. I also noticed that the car maintained the set speed up hill but also down hill (It felt like it applied a little braking by itself) no matter what kind of slope it was going through. I believe that this may affect the fuel economy a little since the car is not coasting freely. When the cruise control is not active and I did have full control of the car, it went downhill a little faster and coasted freely. Does this sounds logic to you all ??? Yes - it's designed to work that way. You're asking cruise control to maintain a certain speed and that's what it's doing. Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted July 31, 2013 Author Share Posted July 31, 2013 Yes - it's designed to work that way. You're asking cruise control to maintain a certain speed and that's what it's doing. I know on my Mustang it doesn't adjust downhill speed when the cruse is on, but it is also a stick... Quote Link to comment Share on other sites More sharing options...
akirby Posted July 31, 2013 Share Posted July 31, 2013 I know on my Mustang it doesn't adjust downhill speed when the cruse is on, but it is also a stick... I think that's only appeared the last 3-4 years. Quote Link to comment Share on other sites More sharing options...
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