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Huge mpg difference between city and highway

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Old 05-17-2019, 11:21 PM
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Default Huge mpg difference between city and highway

I've been taking most short trips (< 5 miles) for the past week and I've noticed my mpg averages only about 15 mpg at best. I do drive pretty aggressively but by no mean extreme. I drive in D mode. These are mostly morning trips with a cold engine.

At first, I wondered if my recent alignment was the cause, since I don't remember getting such poor mileage prior to my alignment.

So yesterday I did a test on the freeway, with engine warmed up, cruise set to 70 mph and in a 10 mile stretch I got 37 mpg from point A to point B, and 33 mpg from point B back to A. I reset the trip meter only when I've reached the set cruise speed (so the extra gas to get the car up to speed is excluded) and I measured both ways to account for any changes in elevation or wind speed.

My question is, is that HUGE of a variation in mpg between city driving and highway normal? Is everyone else seeing this?

Last edited by luder888; 05-17-2019 at 11:26 PM.
Old 05-18-2019, 01:38 AM
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All fuel efficiency ratings goes out the window when you are mKing frequent short trip. The engine is not warm up yet and the Fuel to air ratio is much higher. I sure hope you are not not reving your engine high before your oil is warmed up, that is a big no no.
Old 05-18-2019, 03:42 AM
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I do mostly suburban driving, no highway, 95% in S mode... getting 16 MPG.
Old 05-18-2019, 06:27 AM
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As G Man said, the fuel economy in this car is poor before the engine warms up, so mileage for short trips will suffer. I can get over 21 mpg during pure suburban/city driving (no highway), if the drive is greater than 10 miles, such as for my commute.
Old 05-18-2019, 08:18 AM
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Originally Posted by luder888
...

My question is, is that HUGE of a variation in mpg between city driving and highway normal? Is everyone else seeing this?
Yes.
Old 05-18-2019, 08:56 AM
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Originally Posted by The G Man
I sure hope you are not not reving your engine high before your oil is warmed up, that is a big no no.
No I never do that, I drive immediately and conservatively until at least after the engine oil temperature shows up.
Old 05-18-2019, 09:49 AM
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Those numbers under those conditions sound about right for me also. Cold short trip suburban = mid to high teens. Warm short trip suburban = Low to mid 20s. Warm long highway = low to mid 30s.
Old 05-18-2019, 10:43 AM
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Can confirm, I drive in stop and go traffic or city roads 80-85% of the time and my gas mileage is awful.


I don't worry about it, if I cared about the cost of gas I'd be driving a much less expensive car.

The only thing that sucks is the tiny gas tank in this car. I want 300mi per tank, I only get 200. If it was 300 I would be very happy.
Old 05-18-2019, 10:43 AM
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Can confirm, I drive in stop and go traffic or city roads 80-85% of the time and my gas mileage is awful.


I don't worry about it, if I cared about the cost of gas I'd be driving a much less expensive car.

The only thing that sucks is the tiny gas tank in this car. I want 300mi per tank, I only get 200. If it was 300 I would be very happy.
Old 05-18-2019, 11:18 AM
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Keep your acceleration way, WAY down if you want to get good city mileage. And I mean drive like the most annoying Prius driver.


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