What is your city vs. hwy mileage ?

[Cd]

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.

[TestDrive]

These statements seem contradictory. Would you please clarify?

• 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.
• 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.

[Peter7307]

Cd,
The vehicle is a GM 4 door sedan with the standard (at the time) 3.8 V6 with the 4L60E trans and weights about 1600 kgs (3300 lbs approx)
No mods and factory a/c which gets used quite a bit especially now (Summer here) with temps around the 40 C mark (105 F) and a dark blue car with a dark grey interior.

City MPG sucks at around 11 ltrs / 100 kms ( 21.3 US mpg)
Highway is better at around 7.0 / 100 kms. ( 33.6 US mpg)
These are for unleaded 89 octane.
Running on LPG the figures are about 15% more fuel used.

Normal hwy speeds are 90 / km hr (55 Mph)

Cheers , Pete.

[almightybmw]

I never exceed 45mph on my drive to work, about 3.3 miles. 3 stop signs, 7 lights. Half the distance the speed limit is 25mph, but I coast better at 30mph so I speed a little. On average when I do my best to avoid the red lights, coast as much as possible, I can get 22mpg, over 350 miles/tank. As the wife uses the car as well, has a 1 mile trip, between the two of us winter mpg suffers to 19.5mpg over 1000mi average.


Highway mileage is far different. The lowest I've gotten was 28.4mpg, cruising at 85mph over rolling hills and climbing mountain passes. The best I've gotten was 35mpg, using all the tricks, pulsing up, coasting down, holding the rpms for best torque vs. load, never exceeding 75mph with the accelerator, only by coasting (got 104mph coasting with 5 people down one pass!!). I've gotten that unloaded (just me) and loaded (5 people, full trunk). Both of those are over the same route I can get 28mpg. Driving style makes a huge difference for me.

I'd like to get better intown mpg but stock my car and route don't allow it. I do ride my bike when weather is decent. I hate biking at temps below 25-30*F. Just too cold for this rusty Alaskan. :P

All this figures are an unmodified car, completely stock. Grill block would help, warms the car faster, but the 'stat is sticking, and pushing temps above 220* before it pops open, so I can't risk overheating till I get a chance to change the 'stat. Suck though, since when it opens the freezing radiator rushes in and temps plummet to around 170* and climb very slowly to 185*. I need a garage, some real antifreeze (not dexcool) and a tranny flush. The car needs work badly, and I haven't the time or money right now.



Edit: Neat! Peter you have a similar setup to me, cept I've the 3.1 and the non-heavy duty transmission.

[jamesqf]

This is not what I see with the Insight at all. Though I've never done any long-term measurement (because I just don't do that much city driving), on a fairly smooth highway I'll see anywhere from 65-75 (freeway) to 100+ (rural road at 50-55 mph). In the city? Maybe 40-50 average, if you leave out the slightly downhill stretch through Carson City. I often fill up on the north end of town, and if I catch all the lights will be at 120 mpg or more before I get to the south end, and have to start climbing the hill.

[blueflame]

I dont have a metering device but do fairly accurate log keeping, filling with only 2-3gallons from empty and using the low fuel light.

It really depends on the terrain, AND the skill of the driver to glide with the engine off.

I'm improving all the time regarding engine off glides, this area is the secret I think.

My highway is better too as I'm using drafting much more effectively, without sitting right up someones ass for long periods of time. Quite often I'll slow down to let a bunch of cars or a truck catch up, and then join them in formation for awhile, dropping off after a bit and then looking for a new victim, whoops I mean group of vehicles.

Because my driving is a mixture of short freeway 95km/hr, rural 70-80km/hr and urban 55km/hr I can't really differentiate. My home city is very hilly, so sometimes the motor is off for huge periods of time.



However one things for sure. My ability as a driver to hypermile makes all the difference.

And these skills vary depending on the terrain, speed limits and level of congestion.

I'm getting better at pulling into parking places at 1 or 2mph with the engine off for the last minute or two. Sometimes I'm parked a bit funny. I went from 4.4l/100km to 3.4l/100km when I really concentrated on engine off and cruising with the bunch.

[wagonman76]

I always get worse mileage around town with my cars. Unless I can get it into OD, the mpg is not too good. When I know a light is going to be long, Ill shut the car off, that helps. Or at the very least, Ill shift to N, the mpg goes down about half as fast that way. Same as if Im at a stop sign and theres traffic for as far as I can see (typical on the way to work) Ill just shut it off till a clearing gets close.

Now my 92 Trans Sport van is another story. I can usually get better mileage around town than on the highway. And especially when towing, which I do a lot of with the van. I dont keep a fuel log because it is mainly used for odd short trips and for towing.

[Cd]

Originally Posted by TestDrive

These statements seem contradictory. Would you please clarify?

Yes - I noticed the same thing.
Switching the car back on once warmed up shouldn't take barely any fuel at all.

I need to redo the tests.

I shouldn't post based on memory alone.


( I should point out that I am usually stopped by only one light that lasts less than a minute. If I had a longer trip and more lights, this would be a more accurate test of shutting off the engine at stoplights. )

[Cd]

Thanks for posting folks !
I'm guessing that most of you have automatics.

Jamesqf - how much of your high mileage trips are done coasting with the engine off ?

I find that I can coast with my automatic ( engine on ) pretty well, but when I shift back into Drive while moving, the car shudders and suddenly slows at anything under 50 MPH. ( almost as if I have stepped on the brakes )
This is very unsafe, so I can't do it with traffic behind me.
With a manual, I'm guessing that you do not have this problem.

[MetroMPG]

To clarify: my sub/urban mileage is only better than my highway mileage when using lots of engine off coasting and pulse & glide.

And I don't P&G on the highway any more. Just driving with load.