1996 Toyota Previa LE S/C, Alameda, CA
 

I recently joined this forum and posted a question about EOC with an automatic in the automatic transmissions forum.

I like monobox vehicles (all one unit for space efficiency rather than a three box sedan with a hood, cabin and trunk), hence the handle monobox. I currently have two vehicles, both of the monobox configuration. One is a 1996 Toyota Previa LE S/C and the other is a Class A motorhome which is pretty hopeless to get decent fuel economy out of so I'll mostly discuss the Previa here. The Previa S/C was EPA rated 18 city, 22 highway though using the 2008 EPA rating system the estimate is 16 city, 20 highway. I generally get about 23 mpg average per tank in mixed use and drive fairly conservatively trying to use momentum, avoid using the brakes and in general keeping the changes in speed as gradual as possible and the speed as even as possible. Until very recently I didn't do any EOC in it but used to do that years ago when I had a manual transmission vehicle.

The tyres are rated at 35 psi but I run them at 38 psi for fuel economy and haven't had problems with wear in the middle.

In October 2002 I took a trip from Alameda (near San Francisco, CA) to Las Vegas, NV and back. It is about 550 miles each way. As an experiment I set the cruise control to 55 mph the whole way to Las Vegas and 70 mph on the return trip. I refueled in Bakersfield, CA which is at the southern end of the Central Valley. I had a tailwind going there and the drive from Alameda to Bakersfield is fairly flat with only one significant pass (Altamont Pass). From Bakersfield to Las Vegas there is a lot of climbing going over the Tehachapi Mountains. No air conditioning was used on this trip. Here is the fuel economy information from my log book:
4 Oct. 2002; 64,843 miles; refilled with Arco 87 in Bakersfield; 8.338 gallons; 32.26 mpg from Alameda to Bakersfield
5 Oct. 2002; 65,137 miles; refilled with Texaco 87 in Las Vegas; 10.31 gallons; 28.52 mpg Bakersfield to Las Vegas
9 Oct. 2002; 65,424 miles; refilled with Arco 87 in Bakersfield; 12.508 gallons; 22.95 mpg Las Vegas to Bakersfield
9 Oct. 2002; 65,684 miles; refilled with Arco 87 in Alameda; 11.338 gallons; 22.93 mpg Bakersfield to Alameda

In September 2005 I took the same trip but this time took a passenger and more gear and used the air conditioning. On this trip I set the cruise control to 55 mph both directions. Here are the figures:
25 Sept. 2005; 78,437 miles; refilled with Arco 91 in Las Vegas; 18.549 gallons; 28.63 mpg from Alameda to Las Vegas
1 Oct. 2005; 78,972 miles; refilled with Arco 91 in Alameda; 18.997 gallons; 28.16 mpg from Las Vegas to Alameda

So if you are willing to drive 55 mph you can save a lot of fuel. Driving 70 mph greatly increases the amount of fuel used. I'm not sure about the Previa but I know in some vehicles it takes double the horsepower to do 70 mph instead of 55 mph.

the larger the front area, the more power it takes to go faster..obviously.

as far as the tires go, center-wear is a function of inflation vs weight of the vehicle and has nothing to do with exceeding the sidewall rating.

Sidewall rating is a cold inflation pressure anyway and takes into account heating on a summer highway.