IDM

Guys I thought we might start a thread on tips for getting good gas mileage and perhaps a contest to see who can pull the best mileage on a tank of gas. I have been expirementing lately and changed my gas mileage considerably on the last few tanks of gas.


Please list:

-mileage you are getting
-auto or manual
-year car
-grade of gas
-where you live
-regular temps
-highway or city driving ratio


I will start it off with a few tips:
-open windows/moonroof instead of A/C when possible
-use cruise control when you can
-take off from a stop slowly
-switch from 1st to 3d etc when possible
-get into 5th or 6th gear asap
-for manuals put into neutral and cruise up to stop signs and lights or if you see traffic ahead


Can anyone think of anything else?

kevinballer08

No

and https://acurazine.com/forums/3g-tl-2004-2008-93/mpg-comparison-thread-810386/

ez12a

opening windows and what not only works at low speeds. I personally wouldnt open a window over 35 mph.

Opening windows at something like 80mph introduces a TON of air resistance. Stick your hand out of your sunroof at 80mph. You'll see why rolling down windows is a bad idea. you're better off using A/C at anything 40+.

erdoc48

Usual story-slow and steady wins the race:
Set cruise for just a few mph below the posted limit, say 63 mph for 65 posted speed limit, have car in top gear for as much as possible at cruise, and keep a/c off and vents open (not on recirculate). Keep the windows closed.

Mine is an 06 5AT, and I use 93 gas (91 is typically not available in NJ).

I can usually manage 33 mpg on long cruises (highway). In typical mixed driving, I average 25 mpg or so (typical speeds of 50 mph and some city traffic).

IDM

Just curious why not have recirculate on? I can't deal with smelling outside gas and garbage trucks etc. I always recirculate even with the A/C off.

great gas mileage by the way, I am at 28mph purely city driving right now. Saw 33mpg once going 60mph in 6th gear but wasn't able to keep it for long once getting off the highway.

I think I will change my sparkplugs after a couple tanks and see where that lands me.

erdoc48

Recirculate off only if the air conditioner is off, otherwise, no air circulates in the car. A sparkplug change probably won't do much in terms of increased mpg if the car has under 100,000 miles. With a high energy ignition, a spark would still jump the gap even if the plugs had a widely increased gap from use. In the old days, new plugs would likely make. Difference, now not likely as much.

IDM

yur the man

sddale

Keep it in gear. When it's in gear the rpm's are higher and the car slows faster but it is not using any fuel. If you put it in neutral it is burning fuel to keep the engine idling.

Aman

Yup, it's better to keep the car in gear when coasting. Let the car drive the engine, if that makes sense.

IDM

Please explain how your engine keeps running when you have it at 3000 rpms without fuel?

If your engine is on, it's using fuel, and Id guess that at 700rpms it uses less than anything above that rpm.

IDM

What does having the recirculate on or off have to do with fuel consumption if the AC is off?

ez12a

it gets pretty humid and gross if left on recirc w/o AC. The AC is what dehumidifies the air with recirc on and keeps things nice and dry. It's more of a comfort thing if you're not going to run A/C.

which is why the car's auto climate defaults to fresh air when the temps are right.

Jesstzn

It runs because the drive train is turning it ... no fuel going in .. when it gets to idle speed the ecu regulates it to keep it idling etc.

sddale

^^^What he said.

sddale

Incorrect.

Think about it this way...when you're cruising with your foot on the gas in gear the motor is turning the wheels and when you remove your foot from the gas pedal (giving it no more fuel) the car seems to slow down rapidly because the engine isn't turning the wheels but the wheels are turning the engine keeping it running. Once it gets down to a certain RPM the computer turns the fuel back on to keep it idling. If you put it in neutral the wheels are not turning the engine so it coasts more but it goes into idling mode burning fuel.

nfnsquared

When decelerating (at engine rpm above 950 rpm) with your foot off the gas pedal (throttle valve closed), current to the injectors is cut off to save fuel. If you coast out of gear, then the engine rpm will drop below 950 and the fuel savings will not be realized.

94eg!

I didn't read the rest of the posts, but here is my experience:

-mileage you are getting: 33mpg best on a tank 30mpg average
-auto or manual: manual
-year car: 2005
-grade of gas: 91 octane
-where you live: Las Vegas, NV
-regular temps: 30*f up to 115*f
-highway or city driving ratio: mostly highway, but I did manage a 31mpg two way average over 40miles in the city once.

Tips:
-open windows/moonroof instead of A/C when possible: No. It's best to use AC over 45mph and roll windows down when slower
-use cruise control when you can: Not usually because of traffic
-take off from a stop slowly: This is a must
-switch from 1st to 3d etc when possible: Never. This is bad for your 3rd gear synchro
-get into 5th or 6th gear asap: I'm into 6th at 45 unless going up hill or acellerating to a higher speed
-for manuals put into neutral and cruise up to stop signs and lights or if you see traffic ahead: Never. This is bad for mpg because the ECU shuts off the injectors if you decelerating in gear (above 1200rpm)


Can anyone think of anything else? Following behind other cars helps tons on the freeway. You don't even have to be that close to make a difference. The trick is finding someone that's also going relatively slow and steady to follow behind. Usually you can tell when someone is using their Cruise control. I like following minivans because they are low, yet big and don't kick a lot of rocks at you.

Also read the traffic far ahead. If you are farmilliar with your stop lights, you can usually gauge if it's going to be green or red by the time you get to them. This lets you gradually speed up, or let off the gass accordingly. The less brakes you use, the more fuel you save.

TWiSDiT

iTrader: (4)

-mileage you are getting: 36-38mpg highway (90% of my driving)
-auto or manual: Auto
-year car: 2005
-grade of gas: 93 octane
-where you live: Maryland
-regular temps: 65*f up to 98*f
-highway or city driving ratio: mostly highway

Tips:
- Change spark-plug if u havnt already ( i changed mine at 55k, ngk iridium platinum)
- BG 44k Fuel Injector Cleaner ( did mine same time i changed spark plugs @ 55k)
- Running 32 psi all 4 tires
- USE CRUISE CONTROL

Aretardedorange

iTrader: (2)

How do you get this screen on the speedo????? What button do I press?

nfnsquared

Sorry, but I'll believe 36-38 when I see a MID display with that MPG and a distance of 100+ miles...not 14 miles.

nfnsquared

Covered in your owner's manual. If you don't have one, go to myacura.com and register. Then they will have a link for an online manual for you to use.

stiffdogg06

iTrader: (1)

Pretty much you reset the MID and were driving on the highway?

94eg!

When that DIST states 400+ miles (entire tank), I'll be impressed...

aimtimes100

cruise control saves gas?never heard that one before

ez12a

that it does on flat surfaces. But it doesnt really do a good job of anticipating hills.

I've gotten over 400 miles a tank before, averaging 30mpg. Mostly highway.

But yea, that's kind of a lame picture. I've had my computer say ">36" MPG right after resetting the thing.

T Ho

Negative Ghost Rider. The owner's manual specifically states that there are conditions where the ECM will cut injector pulse width to zero- i.e. no fuel. IIRC, the manual mentions >1200rpm and only certain deceleration conditions, but it does happen. I can sometimes feel the additional engine braking that occurs because of it.

Now, your reasoning would be correct on a carbureted vehicle, but I'm guessing many here don't even know what those are.

Google "Decel Fuel Cutoff." It's been around for a while.

Bearcat94

Contest? What will I win?


I also think, to be fair, you need to run a "Worst Mileage Contest". Now that'd be fun.


Oh, and: The J32 Mile per Gallon Official Competition!! <----- Link




PS: 38 mpg for a 14 mile run?

See the link above and tell us how you do on a 400 mile run.

T Ho

Back on topic-

There's a school of thought that says a more aggressive take off from a stop, along with an early shift (say 2500rpm), is the key to better efficiency. The effect is more pronounced with turbo'd cars, but the idea is that a larger throttle opening increases volumetric efficiency and reduces pumping losses, while the early shift keeps the frictional losses down. Plus, this encourages you to get into the highest gear at the lowest usable RPM as soon as possible.
I knew a guy with an Audi A4 with the 2.0 Turbo that swore by this method, and got some pretty good MPG numbers, too. I can't seem to get comfortable with it.

Don't glide in neutral, for the reasons mentioned in my above post.

Skipping gears is not bad for the synchros, assuming you give the engine time to drop RPM to roughly match the gear you are going to, BEFORE you put the shifter in that gear.

Good tips from 94eg!.

jpgayan

Regardless of what speed you're going it will likely be a benefit to fuel economy if you turn off the A/C and crack a window. Air resistance is negligible compared to the ten to fifteen horsepower draw of the compressor. Multiple windows all the way down at freeway speeds is the only time you'd be better off with the air conditioning on. Also, when approaching traffic or stop lights keep your manual transmission in a high gear with your foot off the gas. This keeps the engine spinning using the inertia of the car instead of burning fuel to spin it. The compression and friction losses will be there either way and it's usually necessary to slow down when approaching traffic anyways.

49er

2006 TL
91 octane 89
auto trans
100% city
freezing temperatures AC off
18 Liters per 100 Km
320 km per tank.
17" Oem rims on winter tires.

Above freezing temperatures
16 liters per 100 km
All city driving.

SouthernBoy

True, but it's surprising how many people don't know this. Which is why I advise people to avoid skip shifting when upshifting. It really doesn't buy you anything anyway.

SouthernBoy

Modern A/C systems don't draw that much HP. But they do draw some for sure. I can attest to excellent mileage on a very warm day at highway speeds with the A/C on during the first leg of a vacation road trip in 2005. The traffic was moderately heavy but moving and the speeds ranged between 62 and 76+ MPH. For that leg, I got 33.94 MPG (calculated obviously).

SouthernBoy

There seems to be a bit of confusion with some folks on this thread about when and when not to use the HVAC recirculate setting.

You should always use the outside air setting when not using your A/C. This ensures a constant flow of fresh air into the cabin, reduces the chance of fogging, and helps to eliminate mold and mildew.

When using the A/C, the same thing is true. If you are using the AUTO setting, when the A/C/ first comes on, it will run in the recirculate mode until the cabin temperature has reached your preferred setting and then it will revert to outside air. Running the A/C in recirculate mode increases fogging and humidity, and lowers the exchange of fresh air. But worse, it promotes coil freeze up and the build up of mold and mildew which produces that unpleasant odor a lot of folks complain about.

So avoid using the recirculate mode unless there is good reason to do so.

Oh, and using recirculate with closed windows can reduce the amount of oxygen in the cabin and cause drowsiness.... not a good thing when operating a motor vehicle.

nfnsquared

Never heard that before. Is that conjecture or is there a reference for that statement?

DMZ

I always shift into neutral and coast when I see a red light up ahead. The problem is the average driver is too dumb to realize that and I frequently get idiots crawling up my ass honking vivaciously. Sometimes they zip around me to make sure they didn't have to slow down until the last moment before they have to come to a stop.

It's really amazing how many people are in a hurry to get to a red light!
.
.

Black_05_TL_6SP

This myth was dis-proven on Myth-Busters. The A/C has enough parasitic loss that it out ways the MPG loss with the windows down.

Black_05_TL_6SP

This was done hypermiling the car a while back. Had 545 miles on one tank of gas and average 34MPG overall. I went 3 weeks or so without having to fill up. It was a challenge to say the least.

Never went over 55MPH
Always accelerated slowly from a stop
Tried not to stop, always slowed down early

ez12a

I would not trust mythbusters as a end-all in the discussion.

Every car is designed differently. But one thing remains certain: air drag only increases as speed increases. There would be a point where the difference between windows and a/c is zero.

The only way to know definitively is to perform an experiment with our cars.

R.L. ina TL

I was complaining about gas mileage till I started driving slower, now its not so much of an issue. But I still plan on changing my oil filter to see if that yields any results.

ez12a

i honestly dont think an oil filter would do anything to help your mpg.

Another tip- remove bike/ski/etc racks when not in use.

-OCD tip: keep the car clean. A slick/smooth car is an aerodynamic car.