accord v6 fuel mileage

31 highway winter or summer? snow tires/chains? Based on this mileage it looks like your car is in good shape and running well.

I have a 2005 Accord v6. I tend to get an average of about 24-27 in mixed city/highway driving (probably more highway miles). I have the nav unit and it has a page that shows the instantaneous mpg. On a level highway at constant speed I often see 35-45 mpg at 60-75 mph. In the city I see 0 when stopped; to 10-15 when accelerating. I'm fairly gentle on the pedal and try to coast (at least not accelerate) when approaching red lights.

15 seems a bit low for city but it could be reasonable depending on rolling resistance (snow / slush) and how aggressively you accelerate. They designed the engine to accelerate the car fairly aggressively if one steps firmly on the pedal. Of course the engine consumes lots of gas to do this.

You could try taking a test drive in a nav equipped accord and look at the instantaneous mpg page.

The winter problem is even more of an issue with cars that get much better economy normally. My wife's car is a '02 Prius (hybrid) and she gets 50 mpg around town in three seasons and low/mid forties in the winter. It has a real-time mpg display, and I decided to see what would happen if we turned the heater up full and opened the windows in town one winter day. I was amazed to see the 5 minute average drop to 25 mpg! I guess the heat has to come from burning fuel one way or another.

Mike

I would be very surprised if the engine comsumed more or less fuel based on the amount of heat being directed to the passenger compartment. There is so much excess heat being produced all the time.

Has anyone else noticed this?

The only way I can imagine an increase in fuel comsumption due to heating the cabin is if the engine got so cold it went into "enrichen the mixture" (equiv to choke) mode. In that case you would feel very little heat from the vents because the engine was so cold.

(wild speculation) It also could be possible that fan motor used more power, but 5 mpg?

I don't actually know, but I'm not sure that is true any more. (It isn't for the Toyota hybrid system, which restarts the engine based on system temperatures.) I suspect engine downsizing and increases in efficiency have meant less waste heat. Cold mpg has always been the pits, even in the old days, and maybe excessive heater use cools the engine enough to impact fuel economy. That's pure speculation on my part, though.

Mike