blackjack hotrods

The more efficient an engine is, the better mileage you will get. This is why a 525hp Z06 Corvette is capable of the fuel mileage it gets. The problem is, with more power, there is a tendency to drive harder thus negating any mileage gains. I am getting 30mpg in the city simply by not driving hard. I accelerate very lightly and when I see a red light ahead of me I pop the car into neutral and let it idle as I coast up to the light. Usually the light will turn green before I get there and I can put it in gear and continue along. That's where you realize the best mpg gains is when you aren't always stopping and starting off again. There isn't even a noticeable increase in driving times. So I would say you would be ok with CAI and catback. You just may not realize any monetary savings for a while due to the initial outlay of money for the mods.

RedBaseBolt

If you put your car in neutral when slowing down you are losing mpg that way. Leave it in gear if it's auto or downshift if it's stick.

It saves more gas then idleing.

blackjack hotrods

In neutral there is no engine braking. And at an idle while coasting at 45mph you are going to try to tell me that I am using more fuel than at 1500 rpm? I'm not going to argue the point but I respectfully diagree.

damage82

what?

RedBaseBolt

I'm not telling you because I just think you are wrong. I'm telling you because it's scientific fact. engine braking SAVES GAS.

Google it my friend and you'll see.

When slowing down, if you put the car in neutral you are wasting gas by not letting the engine slow you down.

Someone who actually knows what I'm talking about please back me up on this one

blackjack hotrods

I am man enough to admit when I am wrong. I stand humbly corrected. From Popular Mechanics:

Q: I have a question about fuel economy. If you are driving downhill, do you save gas by putting your transmission in Neutral and coasting, instead of having your vehicle in Drive? I think that you do but my wife seems to disagree. Can you give me the correct answer, so I can tell her that I’m “Mr. Right,” as usual?

A: That depends. The engine isn’t braking the car going downhill if the transmission is in Neutral, so economy would seem to be high. But if you think the engine is still using fuel while coasting downhill in gear, you’re laboring under a misconception. Most fuel-injected cars turn the fuel delivery completely off when you lift your foot from the accelerator. They still burn fuel when idling in Neutral, so do the math. The amount of fuel burned at idle over, say, a couple of miles of coasting downhill is small, but it’s still more than zero. So if you’re driving a modern fuel-injected car, you’re wrong.

Older, carbureted cars would suck gas through the engine while coasting in gear, even if you turned off the ignition switch. In this case you’d be right.

wski440

By down shifting you have basically changed your engine into a compressor.

Now as the car rolls forward you’ve set it up, by downshifting, so that the flywheels continue around and CONTRIBUTE energy to the compression stage (and all the others) instead of removing energy to move the car against all the frictional forces.

Since less Work is required to cycle around to the next compression stage, and modern cars sense this, less gas is added in the compression phase.

Real world example: You (engine) are pushing a person on a swing set. To overcome the frictional forces you HAVE to keep pushing by a certain amount. Now the person starts pumping their legs to help out; you have to push LESS (use less gas) to maintain the same height of the swinger.

pdub

I'm with you. I hardly believe anyone that says how they get 40 mpg. What is their method? I just don't see a 40+ figure being accurate.

I get 35-37 highway and 25-27 city.

I'll explain my method.

I don't go by how many miles I go by with a full tank to E. #1 I never want to run the bottom of the tank to my engine, shouldn't need to explain that and #2 all pumps will fill at different points, so actually knowing how much fuel you have is nothing but guess work. So no accuracy there. I also don't do the fill up and stop at 1/2 as the gauge itself is never truly right on.

For highway, I have a nice 160 stretch I have to travel often without stops and with speeds variating 50, 55, and 65. The terrain is both smooth and bumpy here and there from needed construction and has a few slight grades. I'll reset the MPG counter on the DIC and run it for 100 miles 1 way record the computer's average, and then redo this process on the way back for another 100 miles, record the average. So at this point I'll have two MPG averages from two 100 mile highway trips. I'll then take the average for those two to figure my highway MPG.

For city I try to use a similar system of a 25 mile commute that will take into account many red lights, stop and go (mostly at night), 25-40 mph zones and even more hills and grades than highway. Again I take the average of two separate trips coming from opposite directions at different times of the day.

I want to hear how these 40+ MPG people get their figures. Yes if your going 50MPH slightly downhill with the foot barely on the accelerator and you reset the MPG counter, then yeah you'll see something like that, but it is not accurate. It'd be accurate if all roads were downhill, 50 MPH, there was no traffic at any time. We know that's impossible. Travel 65 MPH a few miles up a steep mountain cliff slowing down and speeding up to accommodate moderately busy traffic traffic, the computer will not say 40. But hey, let's see, maybe someone will prove me wrong?

blackjack hotrods

This sets up a perfect opportunity for an experiment. I will continue to drive in my current style for the remainder of this tank of fuel and then change to not shifting into neutral and see if and how much the fuel economy actually changes.

dragonkingg5

iTrader: (1)

Highway, I atleast get about 37 MPG. I fill up the tank which is usually 11.5 gallons. I drive on the interstate about 70-80 mph and being auto, the car runs at about 2k-2.5k rpms. after driving on the interstate for a great time, i fill up and look at the fuel range counter again and it sometimes says 410-420. I'm amazed. 35 bucks can get me an average of 400 miles. I drive 400 miles when i go visit my family and its all highway.

City, meh, thats what i hate. think my car is around 28 to 29... stop go stop go stop go traffic stop go some more damn traffic.
The only mod i have in my car atm is CAI. I have to wait for a catback due to the girlfriend taking all my money... J/k i love her. actually getting married next month.


OFF TOPIC if anyone has a tsudo n1 exhaust, pm me. i think thats the exhaust im going for cause its at cheap price and sounds decent.