Why is my car so bad at coasting

[PaleMelanesian]

It's a honda automatic. If you want decent coasting, you have to shift into neutral. If you leave it in D it will engine brake all the way down to a crawl. They're designed that way. Drives me crazy, but when I'm in the Odyssey, I'm shifting D-N-D-N constantly.

[justme1969]

And there ya have it folks!

[jayliu1984]

Originally Posted by PaleMelanesian

It's a honda automatic. If you want decent coasting, you have to shift into neutral. If you leave it in D it will engine brake all the way down to a crawl. They're designed that way. Drives me crazy, but when I'm in the Odyssey, I'm shifting D-N-D-N constantly.

Really? Are you sure about all honda Trans?

In that case, it bring up another quesion, how do you do the D-N-D-N shift. Anything I should look out for? Any possible dmg to the car while doing so?
How much fuel did you save by doing it?

Thanks.

[MetroMPG]

Note on shifting to/from D/N - in most cars, you DO NOT need to press the button on the shifter. You just bump the selector ahead or back - it will stop at N, and stop again at D. This is safer than pressing the button: you don't need to take your eyes off the road to monitor which gear you're going to, and you won't accidentally select R or a lower D gear.

(I'm not 100% sure if all Hondas behave this way. I've seen some Fords & Volkswagens that require a button press when they shouldn't.)

[roosterk0031]

I do it with the Stratus every time I drive it, aslong as it goes between D & N smoothly it shouldn't hurt anything. My auto tranny GM's coast almost the same N or D so I don't bother.

Coasting into stops/corners in where the best gains IMO can be made with an auto tranny. If you have decent hills, where you can crest a hill at 45-55 and the N coast will get you back to 55 or PSL before hitting the bottom. Same down hill in gear cruise set I'd get 60ish mpg instant, in N coast I'm over 100.

It's a pig at idle consumption of 0.5 gph, your is probably closer to 0.25 gph, so your neutral coast at 60 mph would be 240 mpg instant. A neutral coast from 60 to 30, average speed 45, you be getting 180 mpg average during that coast (assuming the 0.25 gph is close).

[PaleMelanesian]

On the Odyssey, lots of neutral coasting (but not pulsing and gliding) is worth probably 2 mpg on the highway. Around town it can be even more. I generally get 25+ mpg in the 16/23 rated van without any more advanced techniques.

Your Accord is probably like Metro described. Just push the shifter forward / pull back without pushing the button. Try it in a parking lot first to find out. Without pushing the button it should move freely between N, D, D3, D2 etc, but not into R.

My Ody is like that, and an '06 Acura MDX I drove was also.

[MetroMPG]

Originally Posted by jayliu1984

- communte is 6km, and 9 possible red lights/stop sighs

(For our U.S. friends: 6 km = 4 mi.)

Short trips like this with lots of stops are not at all ideal for getting good fuel economy, even with neutral coasting where practical. The car never really warms up, and vehicles don't get their best economy until they're completely warmed up (entire drivetrain, not just engine coolant).

(Hopefully you bike in good weather! Vancouver's great for biking.)

Next question: do you have instrumentation? If you really want to get good economy, you should track your results for each leg of your commute. Instant & trip average feedback is key for getting really good at this.

A fuel economy gauge lets you make it a game, constantly challenging yourself to beat your previous "high score".

[XYZ]

Originally Posted by jayliu1984

- the front wheel is quite difficult to turn when I jack the car up, but let's assume brake is not dragging, what else could be the cause?

Assuming it is not in gear, no wheel should be difficult to turn when the wheel is off the ground. There could be several possible causes. Examine it and find where the problem is.

[redpoint5]

Originally Posted by MetroMPG

(For our U.S. friends: 6 km = 4 mi.)

Short trips like this with lots of stops are not at all ideal for getting good fuel economy, even with neutral coasting where practical. The car never really warms up, and vehicles don't get their best economy until they're completely warmed up (entire drivetrain, not just engine coolant).

This is exactly the reason for the poor economy. There is likely nothing wrong with the vehicle. A 6 km drive in near-freezing weather will not warm the vehicle quickly enough. Not to mention the cold transmission fluid, bearing grease, and increased air density being nearly at sea level in cold air.

The solution would be grill blocks, block heaters, etc. Something to get the temp up faster without consuming more fuel. As others have mentioned, neutral coasting will help too.

My warmup times improved dramatically after installing a full grill block for my short 12 km commute. MPG went up quite nicely too.

[War_Wagon]

Every Honda with an auto I have ever driven lets you go into neutral without pushing in the button on the shifter. Bump it forward into neutral, then bump it back for drive. There is a lockout in the shifter so it won't go past neutral into reverse unless you push in the button on the shifter, so as long as you keep your finger off it you should be fine.