i was using towing as an example to your comment "coasting uses more gas..."


Situation:

same road, distance, and vehicles.

one is being towed while idling in neutral, the other is being driven.
which uses more gas?
don't tell me towing it in gear is better.

 

Why not compare what happens when you drive it off a cliff then? You can use even less gas and get there sooner.

 

is it in gear or in neutral?

 

It's in gear, but coasting so therefore is not using any fuel

 

turn off the AC.
Put a nice wax on the car
making sure tires are inflated properly go a long way as well.
Finding the right tires with low rolling resistance helps as well.

 

so since the fuel injectors are off when ur using the transmission brake then wouldnt the car shut off? how are ur rpms even staying up?

 

The transmission keeps the engine cycling. It's in the freaking owners manual if you don't believe me. Someone posted a copy of the page here in another thread.

 

You got me, I guess the outcome would be the same.

I thought you were trying to make a real comparison, if I had known you were just looking for a fight I wouldn't have responded.

You win, you are correct, the OP could save all sorts of gas for his TL by towing it, in gear or not.

 

I am trying to make a real comparison. Not trying to pick a fight, just trying to understand your logic. My original question still stands.

I answered your cliff argument with a joke, because the cliff statement was a joke.

 

Then I don't understand your question. It looks to me like you are trying to compare the gas mileage you get when being towed to the gas mileage you get while driving, which I assumed could not be a serious question.

If you are serious then; yes, getting towed ALWAYS provides better gas mileage than driving. I just thought that was rather obvious, so assumed you were just trying to make a rediculous argument to try to pick a fight.

 

This whole debate stemmed from this comment:


The towing, again, was just an example. Since this has nothing to do with towing, let me put it this way.
Two indentical cars traveling down an infinitely long hill (both are running), one is in neutral, the other in gear.
You are saying the one in gear will use less gas?

 

Absolutely.

 

Since I already mucked the thread enough, I agree to disagree.

Back on topic

Here are some fuel economy test done by Edmunds a few months ago.
http://www.edmunds.com/advice/fuelec...8/article.html

 

I tried setting the cruise control at 65 mph as much as possible on Wednesday driving from Virginia to Maine. Had to go faster a few times due to traffic; also had a 20-minute slowdown at 5 mph or so in Connecticut and a briefer slowdown in Massachusetts. Averaged 58 mph for the trip and 31 mpg. I believe I got 430 miles out of the first tank (stopped at the MA-9 exit off I-495 in Massachusetts).

Going 65 seems SOOOOO slow, but on the other hand, it's nice not being concerned about seeing cops!

 

If have the cruise on 65 on a long trip, I get 34mpg. If the cruise is on 75mph, I get 30 or 31mpg. The time difference, between 65mph and 75mph, on trips < 100 miles, is minimal at best.

 

some just can't understand that idle uses fuel. You explained it well. Let it be.

 

I understand what your saying TzarChasm, makes perfect sense to me!!

 

TzarChasm is correct. When your engine is idling, it using combustion to keep the motor turning. When coasting down a hill and your RPMs are above a certain cutoff (I think it's like 1,600 for the TSX, it'll be somewhere close for the TL) the ECU recognizes the wheels will keep the engine turning and shuts off the injectors. The engine is now simply and air pump being driven by the wheels via the transmission. As soon as you touch the gas pedal, the injectors start injecting and away you go.

 

It's like when you downshift and the rpms go up. They go up because of the rate at which the wheels are turning. As long as the wheels are spinning and the car is not in neutral the transmission, the crankshaft and the pistons continue to move because the wheels force them to. All of this causes the drive belt to still spin which allows your alternator and ac compressor and whatever else, is on the belt, to work as it normally would.

 

well put.

 

i still say go get a hybrid...lol

 

I've been able to get an extra 2-4 MPG out of my 07 TLS 6MT by skip-shifting all the time. (of course this ONLY works with a clutch).

* Accelerate gently from a dead stop and take it up to around 2K RPM
* At 2K, shift up from 1st to 3rd gear and once again accelerate gently to 2K
* At 2k, shift up from 3rd to 5th gear accelerate to 2k and drop it into 6th to cruise.

A few notes...at these RPM's you won't be lugging the engine, but you're running at the bottom of each gear's power band so don't expect the car to jump if you need to move in a hurry; you'll have to down shift at least one gear to get any 'oomph' when you hit the gas.
You may be pissing a few of the jackrabbits off who are behind you when you take off at a light, but not really as many as I expected. I was surprised how most folks seem to be adjusting their driving habits to save some gas.

I also do the coasting to a light thing, and combined with proper tire inflation I'm getting 27-29 MPG around town. Unfortunately that's where I do %95 of my driving in the TLS.

One final footnote...driving this way is absolutely the least fun you can have in a TLS. But it really does matter when you can get an extra 60-70 miles out of a tank when you're paying over $65.00 for a fillup. Boy do I miss the days when mashing the pedal wasn't a big cost consideration.

 

has anyone made any upgrades to their fuel system? (bigger injectors/ fuel rails)
how did it affect gas milage?

 

This should not be a debate as it's based in fact. Like it has been said, with your foot off the gas, rpms above idle, your injectors are off. So here it it is:

Coasting in gear= No fuel used
Coasting in neutral= Idle amount of fuel being used, sometimes higher.

Driving style is #1 on the list. When you see a redlight, let off the gas, don't stay on the gas until it's time to hit the brakes. In an auto, accelerate gently but not too gently. The torque convertor gets more efficient as more power is applied and if you accelerate too easy a lot of your mpg goes up in heat in the auto.

Tire pressure to the max recommended by the manufacturer which varies from 32psi to 55psi. I don't believe in going over and giving up traction to save .001mpg.

The first 60,000 miles in my TL were commute miles and I paid very close attention to mpg and speeds. I found that if I got in the truck lane and did 55mph I got optimal mpg. A little slower and I didn't see a difference. Take it down to 40mph and the mileage got worse.

Contrary to overwhelming popular belief, a K&N will do absolutely nothing for your mileage, not even .0000000000000000001mpg. This is impossibe and I wish people would stop repeating it.

Exhaust will give both power and mpg.

 

So the injectors shut off with foot off the gas at any rpm above idle......nice.....

That answers a question I was going to ask based on the concept from what other people have said that the rpm's had to be over something like 1500 before the injectors would shut off.
If that were true, you would have to engine brake while approaching a red light in order to keep the rpms up.

But wait, if at idle (700 rpm?) gas is needed, but coming to a stop at 800 rpms gas is not needed, they must use something like a throttle positioner device to tell the difference if you are in neutral or just low rpms due to slowing down?

 

Keep it under or around 2k RPM, keep up with tire pressure, don't burn through gears from a dead stop.

As far as the A/C debate goes...i'm pretty sure you would get better MPG with all the windows up and A/C on low vs. windows down (more drag)....atleast on the highway.

 

Each car is different but when I had the TL on the scanner I saw it go into fuel cut as low as 1,400rpm but didn't check any lower than that. When I said above idle, that was a little exaggerated but it's not much above idle.

 

i hear people upgrading to the rsx type s injectors. thats about it though. i dont see where the benefit stands with that tho.... more power? i dunno.

 

^ yea i wonder if there are any benefits.. anyone care to fill us in??

 

Only if the car needs more fuel than the stock injectors can put out which it doesn't. No advantage whatsoever.

 

When I am approaching a red light or stop sign, I've gotten into the habit of putting into neutral and coasting up to it. Now after reading this thread and seeing I am wasting more gas, I believe I won't be doing that anymore. However, I can still see some occasions where I still want use neutral, like rolling into a parking slot. I feel bad for my throwout bearing using my clutch every time I put the car into neutral. I noticed that the gear shift can pop into neutral without it, would it be damaging to do that regularly?

 

true but you travel way less distance in gear vs in neutral. And every manual I've had I'll put it in neutral to coast to a light, much less strain on the car and can't coast in a given gear too long, you'll have to downshift (more wear on the tranny, clutch, engine etc)

 

when i first got the car, my driving habits were really bad... i was getting 450km per tank.. after awhile, i got use to the pedals and the breaking and now i'm avging 600km per tank.

It's all in pedal finesse. The smoother you are, the less gas you use.

 

My thoughts on this as well.
If coasting down a hill in gear -
1) your speed will remain pretty much the same
2) no fuel used, but if you hit a flat spot you must accelerate to maintain speed.
3) As soon as you get to the base of the hill, you must put your foot back on the pedal to maintain current speed

If coasting down a hill in neutral -
1) Your speed will accelerate due to gravity
2) Not need to hit pedal during a flat spot as there is nothing to slow the wheels except ground friction and air friction
3) You can let the car coast longer at the base of the hill only consuming the .5gal/hr rate vs having to accelerate.

I personally take advantage of downhill slopes and try to coast. Using some of the hypermileing tricks, I was able to get 34 MPG for an entire tank of gas with 545 miles on that tank. Given it was boring as hell, it was still good to find out what it could do.

 

My trip computer says I'm getting 27 mpg ave. I drive 1/3 highway, 1/3 city, 1/3 country roads. (06 TL) How much more do you want?

 

You didn't buy a TL to save gas! Vroom! Vroom!

Anyways just read what I hate cars wrote it is 100% correct, most of you that care so much about gas are so light onthe gas that you're actually losing mileage due to torque converter. Just drive normal not too fast not too slow. If you worry about it so much than the TL is not for you. Get a hybrid or a 4 banger

 

I get 14 MPG commuting from work and home. And 8-11 MPG when finding a parking spot for college. But when I'm on the highway I get 30+ MPG so I'm happy especially whe you see the numbers on our counterparts aka the G series, Z series, and the Nissans. Only the Accord 6 CYL are slightly better.

 

i think the issue is with this statement. its not just when your car is in neutral, its when it is in neutral and the car is running. if the car is being pulled and it is off then no fuel is used. if you are driving the car and you coast you are also using little/no fuel, its if you are driving your car and you shift it in to neutral while coasting then you will use more gas than just taking your foot off the gas.

 

My last car was an 06 v6 accord, I think my 06 TL gets better mpg. at least 1.0 mpg avg. For my commute that has been the same for 17 yrs.