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My all-around gas mileage is 23.0. The best I've ever gotten is 30.0 on a trip from Huntsville to Atlanta, which for much of the way is quite hilly. Only 2 people were in the car on those trips.
This past Monday, we took a trip to the west into Mississippi, and the roads are pretty flat. This time, I had 4 people in the car and I did not adjust the tire pressure. Gas mileage computer indicated was 27.9.
Is having two normal-size additional people (maybe a total of 250 additional lbs) in the car enough to drop the mileage by almost 10%?
Speed on both trips was about the same. The computer mpg is very accurate when compared to actual computations (I use Fuely so I can keep records easily).
Yes, adding 250 lbs can have a significant impact - but it's probably not the whole difference - maybe not even the main difference. If the route was not identical, you can't really compare. Elevation changes (total) will have a major impact. Other factors could be at play. Was the temperature the same? Time of year (winter gas)? Traffic? Even different amount of tread wear on your tires over time has an impact.
Last edited by spindlewood; 03-16-2023 at 08:16 PM.
Yes, adding 250 lbs can have a significant impact - but it's probably not the whole difference - maybe not even the main difference. If the route was not identical, you can't really compare. Elevation changes (total) will have a major impact. Other factors could be at play. Was the temperature the same? Time of year (winter gas)? Traffic? Even different amount of tread wear on your tires over time has an impact.
We'll be making trip to Atlanta in a few weeks - just 2 people, tire wear about the same, so we can see what happens.
Not a perfect comparison, as we have a Q5 ('21), but our trip mileage varies significantly. The most significant factor appears to be wind speed and direction (apart from vehicle speed and stop-and-go traffic). Over more than 34,000 miles, temperature has not been a significant factor (from well below 0F to over 90F), and weight also does not seem to be as important. We've gotten 33-34 mpg many times at interstate speeds (calculated, not from car MPG) on a full tank, but we often get 26-28 when going into the wind. Nothing is on the roof, and I removed the roof-rack cross bars. My plot from day one shows a few outliers, including values in the low 20's for in-town driving and a few values over 35 mpg on trips on state roads at 55-60 mph. Occasionally I get the distinct impression that some brands of gas give comparatively poor mileage; we only use Top-Tier gas, all with ethanol (with a few exceptions). Overall we are quite pleased with the gas mileage, and it's better than anything we've ever owned.
Not a perfect comparison, as we have a Q5 ('21), but our trip mileage varies significantly. The most significant factor appears to be wind speed and direction (apart from vehicle speed and stop-and-go traffic). Over more than 34,000 miles, temperature has not been a significant factor (from well below 0F to over 90F), and weight also does not seem to be as important. We've gotten 33-34 mpg many times at interstate speeds (calculated, not from car MPG) on a full tank, but we often get 26-28 when going into the wind. Nothing is on the roof, and I removed the roof-rack cross bars. My plot from day one shows a few outliers, including values in the low 20's for in-town driving and a few values over 35 mpg on trips on state roads at 55-60 mph. Occasionally I get the distinct impression that some brands of gas give comparatively poor mileage; we only use Top-Tier gas, all with ethanol (with a few exceptions). Overall we are quite pleased with the gas mileage, and it's better than anything we've ever owned.
It was indeed quite windy on the trip earlier this week, mostly a crosswind. I suppose crosswind can have an effect, but nothing like a headwind. I've never installed the crossbars so that's not an issue.
Don't dismiss the crosswind for negatively impacting your mileage. On strong cross winds, you'll find that you need to keep the wheel turned slightly into the wind to drive straight. At that point, the tires are slightly sliding which impacts rolling resistance and mileage. Last trip I was on, it was windy, maybe 50/50 cross vs headwind, and I lost 10% in mileage.
I use the Spritmonitor app to track my mileage, 2018 SQ5, 75% Highway, mostly at the 100 km/h limit. Owned from new, well maintained with oil changes and filters at half the recommended schedule. I’m overdue 20k for my spark plugs but the mileage is unaffected.
82,295 Km - average consumption of 9.01l/100km or 25.8 Mpg, it’s my most fuel efficient SUV yet, the 364 HP is bonus.
Last edited by Bernie_schau; 04-30-2023 at 05:38 PM.
Let's also not forget the human factor in MPG calculations. High performance boosted applications tend to make the driver more eager to show off with others in the car. Then there are other factors that come into play. How hard are you getting on it to get into the lane when coming down the on-ramp? Are you going into lower gears to pass traffic? Anytime you get into boost, fuel consumption goes up.
Another factor in MPG is freeway slope. Over very long stretches slope can be almost impossible to detect. Surrounding terrain can create the illusion of zero slope…or even a positive slope when its actually the opposite. In my daily 25 mile commute, the elevation differential is about 375 feet between start and finish. I can’t see anything but a flat ride all the way. A couple years ago, it came to light when I was playing around with my MPG readings. I factored in wind (mild to no cross wind on these trials) to avoid skewed readings and to get a handle on why so much more MPG going from home vs work to home. Dawned on when I did an altitude reading before and after the commute.