Fuel economy better at low gear
6/5/12, 11:04 AM
#1
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In this actual pic I'm in 4th gear at 4000 rpm at 60 mph (try it) and my fuel economy is at 5/6 bars, as soon as I shift into 5th rpm obviously goes down but so does my fuel economy(3/6 bars).. Owner guide says ideal driving gear at this speed is 5th or 6th
Which one is right? What I see or what a piece of paper says?
Which one is right? What I see or what a piece of paper says?
Last edited by HizliBullet; 6/5/12 at 11:05 AM.
6/5/12, 01:24 PM
#2
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Not a chance that your mileage is better at 4K than it would be in 6th at under 2K. That little meter thing is not what I would call accurate - the MPG avg. one is, but I don't think much of this thing.
6/5/12, 01:40 PM
#4
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Although ECU & TiVCT advances have helped low rpm efficiency, there's the old addage that "in the power band" is where the best mileage can be had. 
6/5/12, 07:54 PM
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I played around with the fuel economy screen on my 2013 gt. I tested the car at 35 and 45 mph in 3rd, 4th, 5th and 6th gear (cruise control was on for each test). I found with each upshift, the car always had better fuel economy. Its also possible the fuel economy feature on the new LCD screen is not very accurate either, but thats all I have to go on right now.
6/5/12, 09:08 PM
#9
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Really need to see a video, not a picture. You could have been on a slight decline, off the throttle and slightly coasting, not in gear holding throttle at 4k, etc... Show me a video of you holding 4000-rpms for 30-seconds in 4th gear cruising down the highway while watching the fuel economy gauge.
The fuel economy gauge probably works off engine vacuum levels. In low load conditions, engine vacuum increases.
The reason the Mustang 5.0 6-speed Automatic gets an 18mpg City rating compared to the 15mpg rating the 6-speed Manual is due to the rapid low RPM shifts under light load, allowing the engine speeds to stay below 2000 RPM while accelerating normally up to highway speeds with ease.
When I had my 6MT 5.0, I would hardly ever shift at 2000 rpms, usually 2800-3500 in 1-2-3, then immediately drop to 5-6 for cruising speed.
The fuel economy gauge probably works off engine vacuum levels. In low load conditions, engine vacuum increases.
The reason the Mustang 5.0 6-speed Automatic gets an 18mpg City rating compared to the 15mpg rating the 6-speed Manual is due to the rapid low RPM shifts under light load, allowing the engine speeds to stay below 2000 RPM while accelerating normally up to highway speeds with ease.
When I had my 6MT 5.0, I would hardly ever shift at 2000 rpms, usually 2800-3500 in 1-2-3, then immediately drop to 5-6 for cruising speed.
Last edited by kn7671; 6/5/12 at 09:10 PM.
6/6/12, 07:57 AM
#10
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I know the car well enough to know if the mpg is off and needs looked at. I just don't drive it to try to get super mpg.....it is a muscle car....as you understand...lol
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