2010 Chrysler Siebring and 2003 Mazda Protege driven for fuel savings

[1993CivicVX]

I rented a late model Chrysler Siebring for the weekend and returned about 40mpg. It was an automatic with a final gear ratio similar to a Civic VX (about 2000rpm at 60mph). It was probably a 4 cylinder. I drove 240 miles mostly highway at speeds between 65 and 75mph employing some basic hypermiling: engine on pulse and glide and engine on neutral coasting; slow and steady acceleration and anticipatory driving. I wasn't perfect in any of these methods, but I somehow managed to get around 40mpg. The gas gauge dropped off the full line only about 20 miles after leaving Enterprise (so it probably wasn't full). When I filled up about 10 miles from Enterprise, I put in exactly 6.000 gallons and stopped filling before the tank was actually full. The gauge went just above the fill line. It was on the full line when I arrived back at Enterprise. Just sharing as I was hoping to get 35mpg at the most. I think I may have had a tailwind on the return trip. I drove over 6 miles into the valley in neutral. Usually in my VX I have to pulse at least once during that descent and my speed drops below 60mph for much of the descent. In the Siebring I was at 70mph most of the time for that 6 mile descent. There was some traffic light driving in there as well and some back country road driving and I was moving some stuff (including a mattress on the roof at 20mph but for only a few miles).

I drove a 2003 Mazda Protege yesterday from Logan Int'l airport to Boston and then back to Whately, MA. The trip was 120 miles. The gas gauge was a notch below half when I left the airport and when I arrived it was a notch above one quarter tank. Both cars provided an interesting hypermiling experience as they were so very different. The Siebring rolls nicely and has the low final gear RPM for efficient highway cruising while the Protege is a manual with a ridiculously high strung final gear ratio. 2800RPM at 60mph. I engine on pulse and glided that thing the ENTIRE highway trip! RPM matching was kind of a pain at those high RPMs as I was driving between 60mph and 80mph. I drafted most of the trip and was doing lots of short pulse and glides in order to keep in the draft spectrum as much as possible. I drafted cars and trucks. The car rolls really well as well. All cars roll better than my VX since mine has by far the lightest wheels compared to other normal cars and is overall very light. In the Protege I was able to have some long coasts down the backside of the hills of eastern MA. I have no idea what my fuel economy was, but given the short distance the gas gauge traveled, I figure I was above 40mpg. I don't know how big the gas tank of that car is tho.

[kamesama980]

I agree the protege's are very high strung. My fiancee has an 03 Protege5 (hatchback, called the 'sportwagon' cause it gets a rear sway bar and front strut tower brace. not sure if struts/springs are different) but it's auto and still runs upper 2k rpm range at 65. 2k is about 42 mph. as such it's peak mpg is about 40 at 40 mph (slow as you can go with it in 4th and the TC locked up, go figure) and declines to about 32mpg at 65 mph, 29-30 at 70, etc. when really trying I can get 32 in town depending on where I'm going.