gas mileage

Whoa, that is some pretty bad mileage for a 4 banger. My 1993 Probe SE 2.0 with 139k miles and an automatic regularly got 31 mpg on the highway and less in the city. You should be doing a lot better with the focus.

No. You should be getting at least in the high 20s. Things to check: air filter, sensors, thermostat (does it have heat?), a bad spark plug or wire, dragging brakes (are they hot when you finish driving?)

03 svt, doing good to get 27 freeway, sucks gas around town,, old neon 95 gets 35

I bought an '05 Focus ZX3 about 3 weeks ago: PZEV four-banger, auto tranny,

28000-ish miles. In my first 3 fill-ups my calculated total average fuel economy is 26.70 MPG in mixed use driving. I've built a spreadsheet to track my total cost of ownership - I'll probably post updates from time to time...

FWIW, I just retired a 1993 Escort wagon, 1.9l, 5 speed, 135000-ish miles. The fuel gauge didn't work, so every 300 miles I would fill-up the tank and reset the trip odometer. That car almost always used 10 gallons of 87 octane to go 300 miles in mixed driving. It was just consistent at 30 MPG...

-=RaOuL=-

My wife said I was probably the only one that used a spreadsheet to track my '01 ZX3's mileage. Now I can show her this!

For 95,000 miles, I am at 30.94 mpg overall. That's with about 45% two lane and 55% limited access roads.

Ron

You probably *are* the only one that used a spreadsheet to track your '01 ZX3's mileage. :)

But I track my '03's mileage with a spreadsheet.

Hey cool! I'm not the only numbers nerd around here!!!

In addition to the MPG tracking, I'm tracking every dime I spend on this car and every mile I drive. That should give me a pretty good idea of my total cost of ownership of this car. I'm tracking insurance, registration and I'm even tracking the $5 "saltbuster" carwash I got yesterday... This is something I should've done beginning with a few cars before this one, but going forward I'll be able to use this Focus as a baseline to compare other cars to.....

Oh, by the way, I was mistaken in my previous post - the car is a ZX4...

-=R=-

I have a 04 ZX5 2.3 with auto, normally get 28-29 on trips where the speed limit is 70-75 and about 24 around town (suburbs). My 99 Escort used to get 37 and 30 in the same type use, but that was a 2.0 and stick shift.

John

mad dog wrote:

What sort of winter - summer differences in gas milage do you Focus owners get (assuming that you have cold winters)? I get about 28 mpg in the summer and 25 mpg in the winter (suburban commuting and running chores) in Buffalo, New York.

-- Don

I noticed that with a good inflation of tires (36 ~ 38 psi), you get a lot better gas efficiency. With normal recommended (28 psi?), the tire looks almost flat, so I tend to pump more.

dlkim

While it is true that some over inflation of the tires can reduce rolling resistance and thus improve fuel economy, there are some drawbacks to doing that. One of the main reasons that I avoid doing it is that the tire has a slightly smaller contact patch (hence the reduced rolling resistance) which creates a potentially unsafe vehicle handling profile. Less rubber on the pavement just isn't healthy, even if it helps to conserve fuel. Also, the tire height is changed which slightly raises the vehicle center of gravity, again affecting handling. And the change in tire height could change the readout of the speedometer and odometer leading to a false sense of fuel conservation....

Oh yeah, the tire tread life is reduced when the tire inflation isn't kept at the manufacturer's recommended pressure. This causes premature wear leading to more frequent replacement of the tires, with the associated costs...

Dollar for dollar, a slight improvement in fuel economy by overinflation of the tires seems like a penny wise yet pound foolish approach..

-=RaOuL=-

On Sun, 2 Apr 2006 10:40:29 -0400, "-=RaOuL=-" wrote Re Re: gas mileage:

I'm dragging this out of my 2nd year engineering class (a long time ago) by I seem to recall reduced rolling resistance (hysterisis) is a function of the reduced movement and bending of the tire molecules due to the higher inflation. I may well be wrong, but I don't believe it is the smaller contact area.

That sounds reasonable. I can't see why a bigger footprint *itself* would be the cause of more rolling resistance; it would be the increased deformation of the tire materials with lower inflation that would suck up energy (and - not mentioned - convert it into wasted heat).

On Sun, 02 Apr 2006 15:28:03 -0700, Blinky the Shark wrote Re Re: gas mileage:

That is exactly the mechanism as I recall.

BTW, I haven't seen you in alt.comp.freeware lately. Are you hanging now mostly in Linux software groups now?

I've learned something! I always thought that the larger contact area meant more drag because of the greater surface area in play. I suppose that in a non-pneumatic mechanism that might be the case, but I'm starting to better understand......

-=R=-