I sold my car yesterday. For the time being, that's only relevant in explaining why I was driving a Chevrolet Cobalt from Victoria to Houston. I can get into the sale of my vehicle some other time.
The car was red. Base model Cobalt's should not be allowed to come in the color red. It's arguably a borderline color even for the SS model. But it'd be way cooler if the Cobalt was actually cobalt blue with possibly a metallic shimmer.
Anyway, the information display features an instanteneous fuel economy reading amongst the usual suspects like trip mileage and overall fuel economy plus some gewgaw that shows remaining oil life and tire pressure. As the first 90 miles of the drive form Victoria to Houston are rather boring (while the final 50 are potentially very exicitng depending on the traffic) I amused myself with seeing what kind of mileage I would get at different speeds. At 75 mph, the tach was around 2600 and the instataneous fuel economy showed about 30-31 mpg with some dips down to 29. At 65 mph, the teach was around 2250 and the instantaneous fuel economy showed 36-37 mpg with some dips down to 35. Up and down overapasses, both speeds saw dramatic decreases in fuel economy on the way up and correspondingly higher numbers on the way down.
I have believed for some time that the best fuel economy can be achieved with a steady foot and close attention to the wavy hills and overpasses. Cruise control is good, but it's not great, especially in an underpowered vehicle with a suspect transmission. The Cobalt also produced a lot of wind noise. I got better fuel economy numbers in the Fusion by easing up slightly going up small hills and overpasses and then reclaiming the lost speed on the down slope. Cruise control locks you in to a certain speed, but steady RPMs rock the fuel economy ride.
I also saw a Motel 8 sign that had fallen over. It was one of those 50 ft poles with the big lit sign on top. The pole looked like it had snapped about 20 ft above the ground. Craziness.
1 comment:
In all those trips I used to take to and from the Bay Area, back when Tin was still in school, I did a ton of fuel economy experiments too.
But I actually had to do the math in my head, since I didn't have an instantaneous fuel-economy gague (which was fine, because when you're driving 360 miles, you have a lot of time to think), and the math was likely off due to various approximations I had to make.
That said, I, too, noticed that the best fuel economy is achieved by keeping the RPMs constant, rather than the speed constant. When I have the freedom to do so (which is rare in LA), I often try to keep my RPMs at 2100-2200.
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