2Fast0

Do you guys do that to save gas? is it bad for the engine if u shift to neutral while u r goin 70mph and going down this long hill? Also, since we r talking about saving gas, anyone drive without their spare tire? that's about 30lb you cut loose, will that get u better milage? I have been driving for 8 years now, and never had to use a spare tire in my life.

tqlla3k

iTrader: (1)

What about shifting to Neutral during Long red lights? My dad does that... and it always bothered me. I thought it was because he didnt want to strain his brakes, but at $3 a gallon, I guess I have figured out why.

I need more gas saving tips. I am only getting 22.4MPG, and it sucks driving like this. I want to punch it more often. My cousin with his IS250 gets to punch it all the time and still manages 25MPG

Gas prices are not killing me, But I still want to save where I can.

When is a K&N filter coming out? I think my filter already needs replacement.

In my MT 3000GT(rated at 19/25), I get 24MPG, without thinking. The GT has a Lightweight flywheel and a blitz intake

In the AT IS350(rated at 21/28), I get 22.4MPG, driving like a grandma. I was hoping to get at least better MPG than my 3000GT

STIG

umm why do you want to do that? you probably wont save gas but i am pretty sure it's dangerous when you shift N while you are going downhill.

i get 17.8 MPG in my IS350, but I am quite happy with that cz i got 19 MPG in my RSX while it has only half the power of IS'.

kensteele

I'm not sure how much this is going to save you. Not really worth it. I think putting your car in neutral both on the downhill and at the stop light is a waste and more dangerous than the apparent savings.

Leechiro

19mpg in your rsx? i had an rsx-s turbo and got nearly 25mpg. my is350 gets about 24-25 mpg and i punch it once or twice a day.

i dont see how putting the car in neutral saves gas vs holding the brake at a stop. engine is still running and pressing the brake does not use gas...but i could be missing something.

4TehNguyen

iTrader: (1)

his dad probably used to drive manual, no foot on brake pedal on manual = teh win

I dont see how not having your foot on the brake is dangerous, i can argue if someone rear ends you when you are in D, you will probably let go in shock and the car will move foward some more unlike being in N

javyLSU

iTrader: (21)

Shouldn't be long... They used my car about a month and a half ago to finish engineering the Typhoon intake kit - they told me it would be two months before it's released to market. K&N usually releases the filters before the intake kits, so it should be coming soon...

Javier

2Fast0

when u r driving at 70mph and in 6th gear, ur at maybe 2500 rpm? if u put the car in neutral to coast down the hill, ur rpm drops down to 600 or so. so i'm guessing it saves a substantial amount of fuel............ just a guess though

VitB6

This entire thread was a little weird. The IS 350 doesn't come in manual so why would you put it in neutral? Doing that in an AT car constantly would be bad for the transmission. And for what benefit? Definately not saving gas.

If it was the IS 250, then I would say that makes sense, but in an AT car don't do it.

hogchow

it really depends on where you drive it. if you live in los angeles, getting anywhere close to 20 mpg is amazing.

i get about 19.1 mpg, but that's going down soon b/c i'm going to be doing a lot of city driving this coming weekend. you 24-25 mpg people must live in some commuter town where traffic is only a rare 2 hours a day and is still 30+ mph ;(

kensteele

Putting an automatic vehicle into neutral and coasting is unlawful in many states anyway.

Lets Drive

iTrader: (3)

Shifting your vehicle into neutral does not save gas when coasting. If you want to save gas, leave your car in gear.

When you let off the throttle and start coasting, the cars drivetrain turns the engine, while the ECU signals for the fuel injectors to shut off, going to 0% duty cycle...meaning you save gas. When putting the car in neutral, the drivetrain cannot turn the engine anymore, therefore the engine must turn under its own power, meaning you burn gas at a similar rate that you would by letting the engine idle. Again, to save gas, just let the car coast while in gear...momentum will be your best friend.

DirtySouth

Correct me if I'm wrong, but if you're going 70mpg and you shift into N, it will disengage the wheels from the engine and in turn the engine will rev up even higher until it slows itself down. I don't think thats the best idea.

Now, maybe shifting into neutral while at a stop-light/sign might save you a bit.

RaZoRaMoN

Putting any car whether its auto or manual into nuetral and coasting is illegal in California at least that's what the judge told me when I tried to tell him its why I was a little over the speed limit. I just ended paying the speeding ticket.

al503

I agree with everything you're saying, but I would just like to add that if the hill is not that steep, it may be a toss up between putting your car in neutral v. keeping it in gear.

When you're not on the gas and in gear, your engine is slowing the car down due to compression braking, which is basically the energy required to compress the air in the cylinders in the compression cycle. Racers use this compression braking when they 'heel toe' downshift to help prevent brake fade.

So, it comes down to whether the gas it would take to overcome the compression braking is > or < the gas it takes to keep the engine at idle.