99 Honda Civic MPG

[tradosaurus]

I recently made a 160 mile round trip on mostly highway.

I have a 99 Honda Civic coupe manual that has:
1) New tires inflated to 40 psi
2) new battery
3) new brakes
4) new plugs (NGK V)
5) new spark plug wires (NGK)
6) Mobil 1 oil

During this trip I was carrying a total of 2 adults and two 12 yr old boys.

The trunk was loaded down with baseball bags.

I filled up before I left, reset the odometer and then after the trip filled up again (5.6 gallons).

Doing the math I got 160/5.6 = 28.5 mpg.

Does this seem reasonable? I took my 2005 Ford Freestyle (V6, 3.0L) the day before on the same trip and the display showed 27.5 mpg avg during the trip.

Thanks bunch!

[tradosaurus]

There is no edit button on the original post so the actual mileage was
176 miles.

176/5.6 = 31.4 MPG

[tradosaurus]

Dang! One more thing I ran the A/C the whole time.

[FrugalFloyd]

You didn't tell us how fast you were driving, hills or lack of same, ambient temperature (apparently warm), or traffic conditions. ~31 mpg isn't unusual if you were driving 70+ mph. It is unusual if you were driving 60 mph. I'd expect closer to 40 mpg at the slower speed.

Some cars can show fill variations of well over a gallon. Do you fill your car up consistently at the same pump, facing the same direction, to the same fuel level or # of clicks?

[tradosaurus]

Originally Posted by SentraSE-R

You didn't tell us how fast you were driving, hills or lack of same, ambient temperature (apparently warm), or traffic conditions. ~31 mpg isn't unusual if you were driving 70+ mph. It is unusual if you were driving 60 mph. I'd expect closer to 40 mpg at the slower speed.

Some cars can show fill variations of well over a gallon. Do you fill your car up consistently at the same pump, facing the same direction, to the same fuel level or # of clicks?

I was averaging about 68 mph. Ambient temperature about 75F. I also have changed the fuel filter about 10,000 miles ago (odometer is now at 144,000).

Have no idea about the other info or why it is relevant.

[theholycow]

Sounds about right to me.

Hondas seem more sensitive to additional weight than other cars, based on past reports from users on this site.

The new tires aren't helping either. Worn tires are better for fuel economy; they have less rolling resistance.

[tradosaurus]

yeah you are probably right. The two extra people was about an additional 250 lbs plus the baseball gear in the trunk.

Of course my lard butt doesn't help either.

[FrugalFloyd]

EPA highway estimates are 34, 32, and 29 mpg for the base Civic engine, SOHC VTEC, & DOHC VTEC, respectively. Add the load and AC, & it looks normal to me, too.

[tradosaurus]

I wonder if its reasonable to expect better MPG?

[FrugalFloyd]

Sure. All you have to do is slow down to 60 mph for a ~10 mpg increase. I'd inflate the tires to maximum sidewall pressure, and crank the windows down an inch or 2 instead of running the AC.