hey guys, long time reader, first time poster , i actually didnt know that the straight dope had a message board untill about 1 year after i first found you, oh well, onto the question
my being 16 and broke, and being able to drive has led me to try and conserve as much gas as possible, so i must ask, which is better for your car, putting it in neutral at a stoplight or drive through window, or putting it in park, it seems that they would be the same, but heck, it might not be , im a fan of the first one, no idea why, but hey, thanks for reading and thanks some more for answering
If you’re driving an automatic, there’s essentially little difference between the park and neutral gears according to this recent thread. So your car is probably consuming gas at the same rate as it idles in either gear.
The only differences are that in park, it won’t roll, and it would be harder to accidentally nudge the shift lever and put it in gear. So use park for safety reasons, not fuel mileage reasons.
Why do either? Assuming that we’re talking about a normal car with an automatic transmission, it’ll burn MORE fuel in either park or neutral than it will in drive.
Think it through – as long as your foot is off the accelerator pedal, the engine will take in the fuel/air mixture at approximately the same rate per revolution. Shifting from drive into either park or neutral releases the “drag” of the torque converter in the tranny and allows the engine to idle at a faster rate – generally 50-100 rpm faster. Assuming that your car idles, when stopped and in drive, at around 600 rpm, and idles in park or neutral at 700 rpm, your fuel consumption will increase in park or neutral by about 17%.
In any case, shifting out of drive at a stoplight strikes me as kinda silly, unless the stoplights where you drive stay red for a REALLY long time.
In which case you would save fuel by shutting off the ignition, which I do when the bridges around here open up for boats. Other drivers still have their ignitions on, polluting the air and wasting gas.
You’re quite right, when I answered I had the drive-through in mind. It makes sense to put it in park at a drive-through, where one is typically digging for a wallet, reaching for food, and generally distracted from operating the car. But there are some concerns with shifting out of gear, particularly into park, at a routine traffic light, and staying in drive is recommended.
Not alot to add here, no cites or anything significant.
Just thought as a "do-it-your-dAmn self mechanic that I am being shallow of the pocket and all myself I’d throw in that it’s only recommend shifting out of drive when you are in longer waits as to hold down the heat the engine/tranny contact creates. But as stated there are several other options to consider… sooo… for open bridges, my car is o-ff the second I feel all the bumpers are close enough so that one of those embarrassing gap in traffic moments- I really hate it when you everything looks good and those 2 geniuses up the line decide to scoot up some leaving everyone in front of you al-ot more in front of you… no big deal? Well try putting up with the flashing lights and car horns and other nonsense that bored disgruntled drivers waiting for boats like to hand out like a hand-shake.
Drive-through, eh it’s a toss between park and just stepping on the brake (provided you have all 4 limbs attached to you and have full control over them :D)
Then finally, the loooong traffic light… this one gets a big “N” from me cuz, my car seems to respond quicker from N to D over P to D (automatic tranny ) I often shift to N more for the fact that it cuts engine vibration on the entire car (aka noise) more than for gas savings- I’m a fanatic about saving gas, but transmission positions really aren’t the best way you could “attack” this problem- try a car forum (seriously) in many cases the path to fuel efficiency is also the path to more HP and there’s always a few of tho-se in the car forums…lol
One last situation I’m thinking of with the tranny stuff… remember Hurricane Floyd? I do, know why? Cuz I was one of those “last-minute-nuts” that shot out of Charleston head through Columbia (capital city) and got myself stu-ck the whole daaaammnnn way… in that situation I used “N” cuz there was just no turning your car off you’d be waiting for 20 minutes just to crawl up about 5 or 6 feet and then wait another 20… sooo you don’t want mass murder on the highway… you bet-ter drive that 5 feet or someone back there is gonna catch up to you on foo-t and beat you down, lol… sorry fond memories- we now return you to the relavently discussed topic, thank you for your patience… heh
Hi, Thinktank. I live in Charleston, too, and even the eary nuts had slow going, as you well know. I was really nuts since I did not evacuate. Crazy maybe, but I didn’t get stuck for hours on the “I.”
While driving (be it at stoplights, stop signs or on the road), do not place the car into park in an attempt to conserve fuel. Think safety. Safety on the road is more important than whatever pennies you think you hope to save.
When stopped on the road for a considerable period (waiting for a ferry, waiting for a very long train, etc.), put it into park and turn off the engine. When in a drive-through, put it into park. Better still, foreget the drive-through during busy periods and park it. The walk into the bank/restaurant is good for you and I’ve found takes less time than sitting in the line in the drive-through.
On good weather days, park the car and walk or ride a bicycle.
That’s a good point duckster- about going inside… personally the health aspect is pretty useless in my opinion that leisurely walk from the car through the door to the in-side line… well come on, you’re standing in line where again? The health club? The vegan supermarket? probably more like Burger “Czar”- Home of the whopper that covers your view to your fee-t…
The good point came in where you mentioned parking and going inside due to the efficiency of gas savings… about a year ago they planted a new McD’s in front of my subdivision (yeah, I know >barf< ) the place is basically see-through short of the roof on the place… not to mention I am usually grabbing something in evening hours (which makes visibility easier) … the first thing I do is weigh the drive-through line turn-over rate in comparision to the inside stand-up waiting line turn-over rate. I would have to say more times than not the line inside is progressing quicker… don’t get me wrong, I love to “conserve energy” as much as the next guy in the drive-through line, but somethings… err-it’s just
ri-diiiculous the kinds of crap people pull in the drive-through line because they’re in no real hurry, already being comfy on their asses and all. … so yeah, this would be great chance to cut through the bull and just park your car; you know, have another profoundly deep conversation with the HS part-timer looking for pictures of hamburger/fry combinations and such on the illustrated junk food calculator of theirs.
Btw- Not bashing having a McD’s job, just the typical intellect involved in being one of their employees… while I’m here I’d just like to give a shout out to Aquanetta back behind all those golden fries, yeah grrrl! Super-SI-IZE! You represent gRRL… mmhmm… :rolleyes: …umm- Ya, k time to go… LOL
, i actually didnt know that the straight dope had a message board untill about 1 year after i first found you, oh well, onto the question
, im a fan of the first one, no idea why, but hey, thanks for reading and thanks some more for answering