I have been very disappointed in the highway fuel economy we are getting with our 2019 XC 40 T5 AWD. It is rated, theoretically, at 31 mpg. We have gotten 30 maybe once. Nearly always, it is 24-27. Our driving conditions have been primarily on interstate highways in Kansas, so it is FLAT. But, it is windy. So, our worst experience was about 22 or 23 mpg going into a 40 MPH headwind and driving at a 70 mph landspeed. But even on calm days, on a better road, if we go 75-80 mph, we get maybe 25 mpg. Does anyone have any observations on either why with those conditions we would be encountering this, or what may need attention to fix it?
KHarper
Efficiency falls of dramatically once you get beyond the zone for which the car was designed. Basically air resistance varies as the square of speed so 75 or 80 mph is going to generate a *lot* more air resistance than, say, 55 or 60 mph. See this site for their take on it:
https://www.mpgforspeed.com/
I don't know what speeds the EPA uses for their ratings - does anyone else?
https://www.mpgforspeed.com/
I don't know what speeds the EPA uses for their ratings - does anyone else?
Nothing wrong with driving fast... but you won't get published fuel economy that way as you're driving at the very top of the range of the EPA tests. But if you set it to Eco mode it will help on the highway, you're above where the sweet spot is on the gearing so the engine braking is more significant, so letting it coast off throttle will help.
This page has the graphs for speeds traveled... Even for the "high speed" test the avg is only 48.37 with just a short blip up to 80.
https://www.fueleconomy.gov/feg/fe_test_schedules.shtml
This page has the graphs for speeds traveled... Even for the "high speed" test the avg is only 48.37 with just a short blip up to 80.
https://www.fueleconomy.gov/feg/fe_test_schedules.shtml
Are you calculating with mileage and fuel filled? Or are you using the unreliable and often WRONG onboard calculator? You stated you got 30, that's pretty darn good. So are you driving with AC on? Are you one to "Pre-Cool" the car in Summer and "Pre-Heat" in Winter? Are you driving with ALL consumables OFF or is AC/Climate running, Audio System powered up? Any real fuel mileage calculation needs to be done by how many miles driven and how much fuel was consumed. The onboard calculations are usually wrong by a few mpg. Windy conditions will also drastically effect mileage and your vehicle is AWD so lots of extra weight to help decrease mileage. Hopefully you are also using Premium Fuel like the Owners manual instructs, that does help improve gas mileage as timing can be advanced a little more. Your mileage is within range of every other car so I would not call that VERY BAD at all. Combined average for you car is 26mpg and seems you fall directly into that so good job. https://www.fueleconomy.gov/
24-27 seems to be the median of the 65 XC40 owners who use Fuelly.
http://www.fuelly.com/car/volvo/xc40
http://www.fuelly.com/car/volvo/xc40
Haven't taken a trip yet; but our 'round town mileage is not so great(last two tanks were after the initial "sit for a long time with the AC on while figuring out the car and/or showing it off). If we are getting 20-21 in daily driving, I'd be disappointed to get only 24-27 on the highway.
I miss the 'instantaneous mileage' readout from our last 8 Volvos. Did I skip that part of the orientation to the newfangled infotainment system??? I'd love to find the "sweetspot" for highway cruising mileage.
It was already a big hit to find the T5 "requires" premium fuel. Around here, the per gallon difference between 87 and 93 is about sixty cents...dang. I traded a cute wagon that got about 30mpg average on 87, so a double whammy.
I miss the 'instantaneous mileage' readout from our last 8 Volvos. Did I skip that part of the orientation to the newfangled infotainment system??? I'd love to find the "sweetspot" for highway cruising mileage.
It was already a big hit to find the T5 "requires" premium fuel. Around here, the per gallon difference between 87 and 93 is about sixty cents...dang. I traded a cute wagon that got about 30mpg average on 87, so a double whammy.
I just returned from a long road trip from Chicago, all the way around Lake Michigan. Just over 1,500 miles, over several tanks of gas my average was just about 33 mpg. Saw one tank hit almost 35 and think the lowest was 29.5. Most of this was travelling between 65-85mph. Very happy with the gas mileage, it's honestly as good as my VW golf that was much less powerful, lighter, and without AWD.
We neither preheat nor precool. We do drive with A/C on for most of the conditions I described. The values given are from the computer (which tends to state higher than reality, and when we checked recently, it was high by about 1 mpg over the actual miles divided by actual gallons method). I was comparing to the EPA rating specifically for the AWD model, so that shouldn't be the issue; but I do suspect that the higher speed could be a major factor. We do use 91 Octane (in fact, we recently went to fuel at an unfamiliar station that did NOT have 91 at all of the pumps, so we moved to one that had it).
I just completed a 7 day trip from Virginia to the Grand Canyon - a total of 4,299 miles. I averaged 29.4-29.9mpg the whole time, and I tried it a couple different ways (I filled up so many times...). I tried resetting the mileage after each fill-up for about the first 5 fill-ups and also after each fill-up for 3 or 4, and then just let it ride for the remainder. What I found was that on the highway, which is where I 90% of the time -- I was quite happy with the MPG. When they provide these, it's always in the best conditions in a lab and at a precise speed. I'm happy if I get within 5 mpg of what they indicate.
I did try to use the eco mode when I could, but honestly, I didn't see it making much difference over the comfort mode. I did try to coast when I could.. but really, it was negligible as far as I could tell. I was making good time and my speed definitely averaged over the posted, so if anything I think that would have hurt it.
We went through Virginia, Tennessee, Arkansas, Oklahoma, Texas, New Mexico, Arizona, and then took a return path of Arizona, New Mexico, Texas, Oklahoma, Missouri, Illinois, Indiana, Kentucky, West Virginia, Virginia. This was a bit of varied terrain, but mostly flat for most of the time.
I did try to use the eco mode when I could, but honestly, I didn't see it making much difference over the comfort mode. I did try to coast when I could.. but really, it was negligible as far as I could tell. I was making good time and my speed definitely averaged over the posted, so if anything I think that would have hurt it.
We went through Virginia, Tennessee, Arkansas, Oklahoma, Texas, New Mexico, Arizona, and then took a return path of Arizona, New Mexico, Texas, Oklahoma, Missouri, Illinois, Indiana, Kentucky, West Virginia, Virginia. This was a bit of varied terrain, but mostly flat for most of the time.
2019 XC40 T5 AWD here. Have ranged between 23 and 27 MPG, all city driving with some toll road Hwy speeds. Only one short road trip, so I can't comment on long road trips. Use either Exxon Supreme or V-Power Shell. Have changed the oil three times and expect better gas mileage with latest Liqui-Moly oil change (German). Also, just started using Bestline Fuel System treatment in last fill-up. Have not refueled yet, so don't have a reading (still city driving only) although Houston has vast distances between stops and lots of stop and go and Hwy driving speeds. Don't expect better gas mileage just trying to keep the fuel system clean and lubricated and the vehicle only has 15,600 miles on it.
Are you doing your own calculations or just going off the trip computers? Trip computers take a bit of settling in and generally aren't a reliable source. But you should be getting far better than that. I do better than that with my 6 cylinder that I hammer every chance I get.
I do find that Eco mode on the highway dramatically improves my fuel economy…but even that has its limits. If I go faster than 75, I give all the extra MPG back. I get 18-19MPG in mostly city driving.
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Sent from my iPhone using Tapatalk
Folks using both modes, what is the noticeable difference between driving Eco mode vs Comfort mode?
For me always in Comfort mode, I have seen Highway mileage get to 30mpg which gets my computer calculated average of City+Highway to 25mpg but if you just do city driving then it is between 18-19mpg.
For me always in Comfort mode, I have seen Highway mileage get to 30mpg which gets my computer calculated average of City+Highway to 25mpg but if you just do city driving then it is between 18-19mpg.
Eco mode is very sluggish in accelerating even relative to Comfort mode. It’s not ideal if you’re in stop and go traffic or somewhere where you have to accelerate and brake a lot, like twisty roads.
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I find manually paddle shifting in Polestar and accelerating fast for fun and then get into upper gears quickly gives just as good fuel economy as Eco mode. This is my first non manual transmission car in about 50 years, so I'm used to always shifting. Not much city travel, though, but it is the hilly area I live in that cuts the mileage down the most, and level ground really increases the mileage.
Turbo cars are notorious for being difficult to extract the EPA numbers from.
Reason: EPA highway numbers come from laboratory conditions, steady-state throttle, level-road with no wind resistance. A slight bump of the throttle and the turbo pressure gets contained and ECU adds fuel to match. The EPA numbers on turbo-4s probably running minimal effective boost (all is being bled off) and are essentially just a 4-cylinder. This is why manufacturers have switched to turbo-4s over the V6 popular in the 90s and 00s. For EPA acts like a 4-cylinder, raises the CAFE average, for the customer, acts like a V6 when you hit the gas.
Your wind problem in KS is the same as here in NW PA. We've seen a 4 mpg difference in visiting family in OH on the same trip to-and-back. We've also have rolling hills. I've seen 28 MPG on the freeway, but mostly it is 24-26.
Unless you get a zero-wind day, drive at steady throttle on your flat roads at exactly 55 MPH you won't make the EPA numbers.
Reason: EPA highway numbers come from laboratory conditions, steady-state throttle, level-road with no wind resistance. A slight bump of the throttle and the turbo pressure gets contained and ECU adds fuel to match. The EPA numbers on turbo-4s probably running minimal effective boost (all is being bled off) and are essentially just a 4-cylinder. This is why manufacturers have switched to turbo-4s over the V6 popular in the 90s and 00s. For EPA acts like a 4-cylinder, raises the CAFE average, for the customer, acts like a V6 when you hit the gas.
Your wind problem in KS is the same as here in NW PA. We've seen a 4 mpg difference in visiting family in OH on the same trip to-and-back. We've also have rolling hills. I've seen 28 MPG on the freeway, but mostly it is 24-26.
Unless you get a zero-wind day, drive at steady throttle on your flat roads at exactly 55 MPH you won't make the EPA numbers.
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