a little gas mileage efficiency test
#11
When I coast I am never in a situation where I would need anything other than the brakes and steering. In 40 years of driving I have had exactly two occasions when I needed power to avoid an accident in a situation where I was decelerating...both on the interstate in rush-hour traffic where I had to accelerate into the emergency lane to my left to avoid being rear-ended by someone who wasn't going to be able to stop in time behind me. I wouldn't coast to a stop in these driving situations.
As far as the use of gas, your injectors do not completely shut down under engine braking. And while it is true that your fuel usage is probably about the same engine-braking as it would be coasting, when you engine brake you slow the car down much faster than you would if simply coasting. So you can coast much much further than you can go if you are engine braking.
As far as the use of gas, your injectors do not completely shut down under engine braking. And while it is true that your fuel usage is probably about the same engine-braking as it would be coasting, when you engine brake you slow the car down much faster than you would if simply coasting. So you can coast much much further than you can go if you are engine braking.
#12
Originally Posted by tof,Jul 14 2008, 09:05 AM
When I coast I am never in a situation where I would need anything other than the brakes and steering. In 40 years of driving I have had exactly two occasions when I needed power to avoid an accident in a situation where I was decelerating...both on the interstate in rush-hour traffic where I had to accelerate into the emergency lane to my left to avoid being rear-ended by someone who wasn't going to be able to stop in time behind me. I wouldn't coast to a stop in these driving situations.
As far as the use of gas, your injectors do not completely shut down under engine braking. And while it is true that your fuel usage is probably about the same engine-braking as it would be coasting, when you engine brake you slow the car down much faster than you would if simply coasting. So you can coast much much further than you can go if you are engine braking.
As far as the use of gas, your injectors do not completely shut down under engine braking. And while it is true that your fuel usage is probably about the same engine-braking as it would be coasting, when you engine brake you slow the car down much faster than you would if simply coasting. So you can coast much much further than you can go if you are engine braking.
Coasting in neutral WASTES MORE GAS than coasting in gear. Period.
#13
Originally Posted by tof,Jul 14 2008, 05:05 PM
As far as the use of gas, your injectors do not completely shut down under engine braking.
#14
Has been a standard on cars since the mid 90's.
I do the same type of driving, however I would not call it driving like a grandma. Maybe accelerating like a grandma, but part of my driving philosophy is energy conservation, which includes taking turns with the least amount of decrease in speed. Results are still doing 50mph down the twisties (which make up 80% of my daily 45min commute) which is the same I would do when out for a fun drive, just less acceleration between turns so no need to brake except at stop signs.
I do the same type of driving, however I would not call it driving like a grandma. Maybe accelerating like a grandma, but part of my driving philosophy is energy conservation, which includes taking turns with the least amount of decrease in speed. Results are still doing 50mph down the twisties (which make up 80% of my daily 45min commute) which is the same I would do when out for a fun drive, just less acceleration between turns so no need to brake except at stop signs.
#15
OK...I guess that's possible, given the sophistication of the modern ECU. I guess the least little signal from the tps gets the injectors firing again?
You have me rethinking that bit of my driving strategy.
However all this reminds me that one of the most frequently overlooked tips for improved mileage is....avoid braking. Brakes turn energy (from fuel) into heat. Heat does not do anything useful from a mileage perspective. So when you are driving, plan ahead. Decelerate with engine braking only...by planning your deceleration. A driver who does a really good job of watching things well out ahead (which you SHOULD do anyway) and who plans accordingly for things like stop light timing, folks stopped for left hand turns, etc. By planning ahead you'd be surprised how much braking you can avoid. And your pads will last longer and your wheels will stay cleaner.
You have me rethinking that bit of my driving strategy.
However all this reminds me that one of the most frequently overlooked tips for improved mileage is....avoid braking. Brakes turn energy (from fuel) into heat. Heat does not do anything useful from a mileage perspective. So when you are driving, plan ahead. Decelerate with engine braking only...by planning your deceleration. A driver who does a really good job of watching things well out ahead (which you SHOULD do anyway) and who plans accordingly for things like stop light timing, folks stopped for left hand turns, etc. By planning ahead you'd be surprised how much braking you can avoid. And your pads will last longer and your wheels will stay cleaner.
#19
Originally Posted by tof,Jul 14 2008, 10:17 AM
OK...I guess that's possible, given the sophistication of the modern ECU. I guess the least little signal from the tps gets the injectors firing again?
#20
live and learn.
As far as "old fogie" driving...The type of driving I described, especially the techniques needed to avoid braking, will make you a better smoother driver and a safer one to boot. If you take smoothness as a challange you can really get into it on a 10 minute in town comute.
And I still drive like a bat outa hell every now and then...although I am resisting that impulse long enough to finish this little one tank test I'm on at the moment.
As far as "old fogie" driving...The type of driving I described, especially the techniques needed to avoid braking, will make you a better smoother driver and a safer one to boot. If you take smoothness as a challange you can really get into it on a 10 minute in town comute.
And I still drive like a bat outa hell every now and then...although I am resisting that impulse long enough to finish this little one tank test I'm on at the moment.