Do you "coast"?

[Matt Timion]

Fiberglass wheel covers will be a project of mine in a few months (maybe next spring). I first need to do the engine swap, install cruise control, put the new wheels on and do other small modifications like the PCV catch can or maybe the A/C kill switch when accelerating.

Eventually though, I'll get those damn wheel skirts made. Another problem with it though is that the insight rear wheels are considerably inwards (toward the center of the body). On all other cars the wheels stick out. Maybe the trick is to get super small wheels too, which I will NOT do considering I just spent a small fortune on my HX wheels.

[Paul Osborne]

I drive an automatic and am a big time coaster. Heck, I’ll crawl as far as I can and relax while doing it. Part of smart driving is knowing how much gas you need to burn between point A and point B. It’s always interesting to see SUV’s and trucks roar around me so they can get to the red light first. Should I pat them on the rear bumper and congratulate them for winning the race?

Coasting is for relaxation, but hurrying it up breeds anxiety.

Paul Osborne

[SVOboy]

Originally Posted by Paul Osborne

I drive an automatic and am a big time coaster.

But do you only coast coming into lights or other sorts of stops or do you do it when going down hill or other times when you'll be starting back up at relatively the same speed? The thing with my auto is that it always reengages in first gear and then has to fly around to find the right gear and it doesn't like it at all.

[Paul Osborne]

I pretty much coast as much as I can. If I don't need to burn the gas I let up. I'm a very patient driver - I can even rejoice in a traffic jam!

My wife tells me I drive like an old lady. :-D

If I think there is a stop sign up ahead, my foot is already off the gas. Remember, I'm the guy who wrote the book Take Your Foot Off The Gas. ;-)

Paul Osborne

[SVOboy]

This will hurt fuel economy more than it will help it. In an effort to save gas, Honda ECUs turn off the fuel injection if the throttle is closed AND RPMs are higher than a specified amount (900RPM, I think). So if you are cruising down a hill with the car in gear and the throttle closed, the car is burning no gas (provided the engine is spinning faster than the threshhold RPM). If, on the other hand, you put the car in neutral, it has to burn gas just to keep running.

Someone mentioned coasting downhill and someone said they above, I've heard this a lot in specific to honda's, anyone know any solid information or where to get it?

[rh77]

I read somewhere that putting the car in neutral actually uses more fuel -- here's the theory. When you lift your foot off of the gas, you allow the car to remain in vaccum, compression of the engine is used to slow, and minimal fuel is delivered. If you shift to neutral, you're asking the car to use deliver fuel just as if you are idling, which which may be more than allowing compression to slow you down. If you have a manual, the recommendation is to stay in top gear until the engine is about to bog, then shift to neutral, or cut shut the engine down.

RH77

[SVOboy]

That's what I've heard about honda in particular, but talking to drdisco from h-t, he suggested that mehbe the cost of decelleration from engine breaking would mean less time to coast or more need to accelerate after coasting, which might make coasting in neutral a more viable solution.

[rh77]

Over at h-t there's a thread that really tries to figure this out (and really belabors the issue at times)...

http://www.honda-tech.com/zerothread?id=1404584&page=1

Essentially the fuel injection system (including DPFI) pulses to lean out the mix on closed-throttle, whereas the fuel injectors are on full-duty during idle to maintain a certain RPM. You're correct in the fact that is may slow you down too quickly, so then fuel is to be used to catch back up to traffic, so finding that sweet spot would yield the best economy. This would be much easier on a manual, because my automatic gets all confused when I shift to neutral down a hill going 55-60, then shift back to D4, which causes some drag and may have negated the whole fuel savings while coasting (basically it seems to go into 3rd then down to 4th).

The best thing to do is to cut the fuel injection entirely when coasting, perhaps? That way you get to keep all that fun safety stuff running(if you have it) like power steering and power brakes.

RH77

[SVOboy]

Power steering psssh...I don't need that. I would like my power brakes back though. Sometime soon I'm going to start experimenting with shutting to car off to coast.

[rh77]

Originally Posted by SVOboy

Power steering psssh...I don't need that. I would like my power brakes back though. Sometime soon I'm going to start experimenting with shutting to car off to coast.

I had a '97 Civic DX with no power steering and no A/C. During the summer I lived out in the country and commuted to work about 40 miles away. (This was in Ohio) - out on the back roads, the lack of P/S was great -- you could really feel everything the car was doing in corners (lots of fun). 30-40 mpg, manual trans. What a great college car. Traded it on a '99 Civic Si (best car I had). Then the EVO bug bit me and I treaded into 18 mpg territory. It lasted about a year -- too many glitches in the tranny. Traded it on the TL (no regrets, it was a rush, but I'm over it).

RH77