Thread: Neutral Coast Not So Great for Fuel Economy

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This is very interesting and seems to be true for B14's.

I've noticed this with monitoring my driving with a ScanGauge and when I was personally coasting, not seeing that great of an improvement.

One time I was on a long trip and was starting to hit the Low Fuel light. Now problem was I was driving from West VA to VA via 64, and there are not too many gas stations in the area.

To safe on gas I coasted down the hills, and no not down the very steep hills (didn't want breaks to overheat). But anyway, I didn't see any improvement in gas mileage by coasting. The MPG was around 32 MPG, which is 1 less then the usual highway MPG's.

I dunno. What about big hills?

Just stick it in the highest gear and go down.

I've noticed with the ScanGauge, while in gear the MPG goes to "999999" a lot more then by coasting.

I assume ScanGauge shows "9999999" when the injectors are off?

whats the obsession with mpg?

I think you got the best mpg your ever gunna get little tricks and tips only work to certain point before it gets to just become outrageous. Vad youre a cool guy but you gotta get over it with the mpg threads man. Buy a hybrid or a smartcar if your so worried about mpg.

That is said with love

Haha Rob, well since there is no other place to talk about MPG's gotta talk in General discussions.

Whats the obsession? I drive a lot in the city, and getting 21 mpg sucks

Now if my sludged up SR was able to give my 37-38 MPG on the highway twice already, I think it's very doable.

Hybrids are too slow

Anyway, I like to look on the other side of the spectrum. Yes I like a fast car, but when I'm not going fast I wouldn't mind getting some descent MPG's. Otherwise there is no point to ever go slow

There are hybrids getting about 35-40mpg. Besides the Insight or the Prius(sp) they get like 50mpg or some crap i dont follow up on to much hybrid stuff.

But the 2008 Camry hybrid -

Under the hood, the Camry Hybrid is fitted with a Hybrid Synergy Drive system consisting of a 2.4 liter DOHC 16-valve VVT-i four cylinder engine, and electric motor producing a total of 187 horsepower (HP), along with an electronic continuously variable transmission (ECVT).

The official gas mileage estimates for the 2008 Camry Hybrid are 33 city/34 highway miles per gallon (MPG).

I just think your expectations are way to high looking to get 40mpg is kinda crazy. Thats JUST my opinion. My versa isnt even getting 38mpg. The window sticker says something like 30 city/34 highway. For the versa 6 speed. Thats grandma driving it.



Its hard to have both, its possible but hard. I think you are getting decent mpg, your city mpg isnt to great but it seems you're getting great highway mpg.

I built my car with several factors in mind, and mileage was one of them. Currently I avg only 20mpg because everytime I pass someone I use a full gallon

But my goal for the car was only 27mpg avg. I think with gas prices these threads are nice to see. BTW the computer cuts injector duty while engine braking, but not on all cars. Some cars keep pulsing injectors to keep the cat lit for improved emissions.

On our cars you want to engine brake as much as possible to save gas, or just lean out your idle afr to 17:1.

40mpg highway is do-able...if you can manage to drive like a grandma and do more long stretches.

I kind of want to get my speedo going again and stick some gxe wheels on the nx and see what it can do

I cant believe people still coast on neutral. Thats one of the reasons I hate automatics. Engine braking is good for your brakes, is good for MPG and its a more efficient way to drive around.

Thats new cars, new cars tend to get crappy MPG's as is. They are freaking fat/heavy.

The only cars that I've seen getting somewhat impressive MPG's that are not Honda 1.5L/1.6L/1.7L slow are the Nissans with CVT transmissions. I'm truelly impressed at those, everything else is crap.



Holy crap, how fast are you passing them?

I would love 27MPG average, but mine sits at about 22 MPG average ha.

Interesting, about the cat. If our cars do that then, would it be possible to reprogram that with a Calum Real Time?

Good idea on the idle FPR. And since you really don't idle all that much, worrying about overheating shouldn't be that bad. Actually it might help the engine warm up quicker for cold starts... right?



Well the both times I did 37-38 MPG highway, I beat on the car a little bit. Redlined at least 2 full times, and other times up to 4-5k rpm to pass.



That is exactly the purpose of this thread. To show people that neutral coasting is not all that great. I was surprised myself because I recently started coasting more, but time to go back haha.



Another interesting thing that I noticed. When coasting down a hill (at around 30-35mph) and not going all that fast, coasting in 5th will make the ScanGauge show 100-150 MPG, since I am not going really fast enough for 5th gear the car will sputter and shake a little bit.

So I decided to do downshift to 4th, the car then drives better and ScanGauge will show the MPG of "999999" or injector duty cycle off.


This just shows that even coasting in the highest possible gear is not always good.