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Old 01-22-2009, 05:43 PM   #1 (permalink)
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Question What is your city vs. hwy mileage ?

A while back, MetroMPG and some others here were surprised to see that their around town mileage was much higher than their highway mileage.

A car such as MetroMPGs' could get around 60 + MPG ( US ) on the highway, but easily over 80 + ( and over 100 at times ) in the city.

I have a SuperMID trip computer in my car which is a 1993 Honda Civic DX with an automatic. I don't have cruise control. My tires are aired up to max sidewall pressure ( 44 PSI ) I also have a grille block and 1/3 belly pan installed which helps warm up times ( and aero at highway speeds )

My drive to work consists of 5 lights - 3 of which I know the timing. There is a hill that I coast in neutral for 2/3 of a mile. I only coast when there is no car behind me for a good half mile or so.( so not very often ! ) The speed limit is 45 and 50 MPH at the top of the hill.
I find that switching the car off for the one minute or so of a light does not seem to really help much ( my trip average registers less than one MPG difference ) , and I feel uncomfortable doing that, so I don't use that trick.

Despite doing my all out best, the best that I could do on the 7 mile stretch of road that I take to work, is less than 40 MPG.

Much to my surprise, 50 degree weather will drop my trip average to as low as 28-29 MPG. 68 degree weather results in 38 MPG ( What a difference a few degrees makes ! )

On the highway at around 60 MPH, I get around 48 MPG- to a high of around 50 ish.

Since the SureMID trip computer shows your instant MPG reading ( actually Km/ L which I convert to MPG) I noticed that my instant reading is around 18 MPG when I first start my trip ( cold engine ). As the engine warms up and I get to around 45 MPH, my instant readout goes up to 85 - 90 MPG.

( To those not familiar with an instant readout like a SuperMID has, the figure is constantly changing. The slightest pressure on the accelerator will drop the figure from 90 + MPG to 30. Lift up on the gas, and you are instantly getting over 100 MPG - till the car slows and you have to press the gas again )

I had assumed that when the comments were made about the super high mileage figures, that everyone was talking about their instant MPG readings and not the trip average.
Much to my surprise, this was not the case.

So, I'd like to ask everyone that has a trip computer about what kind of mileage that you get in city driving ( not rush hour - just rural roads )
In your response, please tell how much is coasting / engine off ... etc.
What is your figure without the engine off ?

Also, I'd love to see what you guys that have an automatic are getting.

One more thing that I found by using the SuperMID, is that a light that last around one minute cost me almost 2 MPG on my trip average.

Last edited by Cd; 01-23-2009 at 09:52 PM..
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