SouthernBoy

I wish I could point you in a direction where this was stated as a scientific fact, but I cannot and am not going to go searching for same at this time. Let's assume you have three people in a car with the windows up and recirculate selected. These people are going to be consuming oxygen and creating carbon dioxide, not to mention that each one produces an average of 110 BTU. Add to that the fact that our entire skin surface also breathes. Now granted, even with a closed cabin, a small amount of outside air will make its way inside due to seals not sealing completely, body shapes and angles, and a few other factors. But these three folks are still going to be consuming oxygen faster than it can be replaced.

It if is just you, then you have more of a buffer, but I know for a fact that you are at risk of fogging up windows because I see it rather frequently.

Bottom line is, use your fresh air setting as much as you can. You lose virtually nothing and gain pretty much everything... unless a freshly dead skunk is lying in the road up ahead.

nfnsquared

Then I'll assume it's largely conjecture, and so is this:

When we inhale, we only use a small amount of the oxygen in the atmosphere (inhale=21% oxygen, exhale = 17% oxygen). The cabin is vented to prevent over/under pressurization. I think it'd be virtually impossible to deplete the ambient oxygen supply to a point where blood oxygen levels would drop below normal, even with 4 people in the car.

1995hoo

I turn the recirculate on and off from time to time while driving for various reasons. My neighborhood is located about two miles from the closest subway station and the main road that goes past here is on the bus line that serves the subway. That means it's not uncommon to get stuck behind a bus belching out stinky black diesel fumes. If I come up on a bus, or on a truck that does something similar, or a car that's burning oil, I always turn on the recirculate as soon as possible so as to avoid having that crap sucked into the car by the AC. Same goes for if I stop at a red light and I see someone in front of me smoking.

The other time I always use it is if I'm driving in a very bad-smelling area. The New Jersey Turnpike between Exits 12 and 13 is a prime example (I seldom go north of Exit 13), as is the West Shore Expressway through the Fresh Kills landfill.

Otherwise, though, I tend just to set the climate control on Auto and let it engage or disengage the recirculation as appropriate.

Regarding the original topic of fuel economy, in theory the best thing to do is to drive at the slowest possible speed that allows you to use the highest practical gear. ("Practical" recognizing that on a neighborhood street, for example, you shouldn't be going fast enough to be able to use 6th gear.) All that crap you read in the media about "cars get their best mileage at xx mph" is all bullshit because every car is different in terms of engine, gearing, etc. My TL does substantially better at a sustained 70 mph in 6th gear than it does at a sustained 60 mph in 5th because the engine doesn't have to work as hard.

I have almost seven years' worth of mpg data in a little booklet I keep in my driver's door pocket and the proverbial bottom line I come down to is that the 6MT TL loves the highway and hates the city. Simple as that.


BTW, regarding the point DMZ makes, I try to see what the light for the other street is doing as I approach a red light. I like to try to time it so that I can hit the light as it changes, if possible. When I'm first on line at a light I almost always watch the other light (if I can see it) and shift into 1st when it turns yellow so that I can go immediately. I hate sitting behind the people who take several seconds after the light turned as if they're not sure it really turned.

SouthernBoy

Nice response and good info to backup your position.

kela123

LOL this is gonna sound crazy but i just drove for a hlaf hour, 7 mls dist. No heat or AC, on the streets( brooklyn) traffic. AVG MPH:13 AVG MPG:13

Is there some thing wrong or is it normal ??? Got me worried

Aretardedorange

iTrader: (2)

Well I found out how to use that screen and I am getting 17 MPG. This is a mix of mostly highway+city driving.

Aman

Were you stopped or idling a lot?

94eg!

As stated previously, this actually works against you a bit. If you coast down with the car in gear, it shuts off the injectors till your down to about 1200rpm. You can feel the car jerk when they kick on again.

I rarely coast in neutral unless I need to be below 1200rpm.

Hondaforlife954

I get about 31-33mpg on the HUD but when i calculate it when i fill up its about 29-30mpg when im driving at a normal rate. But it is way too much fun to slam that petal down when getting onto the highway. My TL gets better gas mileage then my modded CBR954RR.... but i hammer the shit out of that. If you cant afford gas and you need to get the best gas mileage possible then why did you buy a TL??

ez12a

7 miles in half an hour? Yea, he's in stop/go traffic, idling for most of the time.

The acceleration and braking is what killed his mpg.

Jeremy Clarkson on Top Gear explained it the best: If you're braking, you're literally throwing money away. (Unless you're going down hill...but then you need to get back up the hill eventually). The gas that got you going just went to waste.

T Ho

I thought of an unconventional tip that I noticed a few years back, still true today-

If I leave work no later than 455pm, I have a pretty clear road home (only 6 mile commute). My average speed is 1-2mph higher, therefore my average MPG is 1-2 higher. If I leave just 15 minutes later, I catch way more traffic, longer delays at lights, and lower average speed, lower MPG.

So, I'm making it a point to be at the end of the lot at 455pm.

1. I'm an efficiency aficionado. It's a game of sorts for me.
2. Some of the gas put in your car was paid for in blood, literally. I try to be mindful of that.

Hondaforlife954

Good points. Its always fun to try and get the best mileage. But i hate it when these 18-21yr old kids on here complain about mileage and want help. GO buy a CIVIC!!!!!

kela123

well yeah it was heavy traffic and a lot of lights...so thats normal i guess..

SouthernBoy

Fuel economy is not a priority with me. In fact, when I am in the market for a car that will serve as my personal driving machine, fuel economy doesn't even enter the picture. If the car I buy happens to get good mileage, I consider that to be icing on the cake but that's it. There have been times when I really tried to stretch my mileage and used techniques to get the most from a gallon of fuel, but those were times when I just wanted to see what the car could deliver.

I am far more interested in the driving experience and to me, that means a car that has a measure of performance. Now if I was vacillating between two cars of nearly identical attributes and such I couldn't seem to find a separating factor, then mileage would enter the picture as an item in my decision. But that's it.

DMZ

I think you're assuming I have an automatic transmission, but mine is a 6MT, not a 5AT. So when I go into neutral, the engine is revving at the same speed as if I'm stopped at a red light or stop sign.

Overall though, the less stop and go, the better your gas mileage. That's why I typically try to go routes with the least number of lights.
.
.

Jesstzn

Works the same in either one .. no fuel being fed until it reaches the lower RPM.

jda123

Also keep in mind that engine drag will slow you down and decrease your distance of a coast. If you have a long way to coast it out, or if you would have to accelerate to get back up to speed, then idle fueling for longer distances at more speed would probably be better than engine dragging you shorter and slower where you have to regain speed.

I would rather neutral coast it into a light for a quarter of a mile and only have to accelerate 10 MPH, then engine drag it for an eighth of a mile and have to accelerate 25 MPH.

marTL51

i usually get anywhere from 21-25mpg and that driving highway alot how do u guys get in the 30s and higher??

ez12a

Set Cruise and dont go above 65 mph. Easy to get at least 30 mpg that way.

Stay in 6th gear for the least engine resistance. I find that I can coast a pretty darn long way until I need to start downshifting. You can coast in 6th until just under 30 mph.

marTL51

i set it for 70 but i will deff try under 65. and that will even work with an auto?

ez12a

it should, but also how do you drive? Do you take time to accelerate or do you try to get to speed asap?

Try accelerating slower, anticipating red lights, and braking less (obv brake when you need to) just coast more. When I drive miserly i dont shift above 2k if i can help it. For auto you can either sport shift or manipulate the gas pedal to get the transmission to shift.

Also get in the slow lane if you're going to drive miserly. Gets people off your back when you drive at least in CA.

marTL51

ive learned to take my time accelerating bec of gas lol
but yeah thats a good call i will because i drive in mass alot and they all tend to be massholes.. but thanks for the help ill let know if the tips worked once im done with this tank of gas.

1995hoo

The word in boldface is the key, unless you were going down Ocean Parkway and perfectly hitting all the lights on the green wave.

kela123

LOL man i'am with u on this, i did the belt today and got around 26MPG with occasional high accel btw stillwell ave and ocean PKW exits .so i gues im stuck at avg 10-13 on the streets.

kela123

It shouldnt be and im pretty sure is not a priority with anyone who bought a TL, but just for comparison sake and to make sure nothing is wrong with the car always good to get an opinion

jpgayan

I put a pretty heavy emphasis on performance but fuel economy is definitely part of the equation. If performance were my primary consideration the TL would pretty much be last on my list. For not much more money I could have picked up an Audi S4 but the difference between 20mpg and 29mpg on the freeway adds up in a hurry. I calculated $4900 difference in gas over 90,000 miles of freeway driving. Granted, I'm sure the difference in city mpg is much closer so real world savings would be a bit less. The simple fact is that for all of my needs (space, fuel economy, reliability, quietness, looks) and my current and near future financial situation, the TL-S 6MT was the best overall choice. If fuel economy, and hence money, wasn't an issue then the TL wouldn't have even made my top five list.

SouthernBoy

I see nothing wrong with that. I would too were I having concerns.

SouthernBoy

In July 2004 when I was getting close to getting my '04 manual TL, I had narrowed down my choices to the following cars, in no particular order:

• Jaguar Type X
• Cadillac CTS-V
• Ford Focus ZTS
• Acura TL

Interesting mix. You should have seen the narrow minded auto bigots on this website giving me all kinds of grief about even mentioning a Ford Focus in the same breath as the vaulted Acura TL. Why, you'd have thought I pissed in their beer... or was it wine? Their inference was that I couldn't afford a new TL so why the hell was I wasting their time with so much dribble. Never mind that they didn't even know me, what I did for a living, and my financial status. Well enough of my rant for something a few ignorant a-holes chose to write almost seven years ago.

I was leaning strongest towards the CTS-V and the TL and with some of the rear end problems the CTS-V was seeing, I wound up with the TL; which was not a bad decision at all. With me, it's quite simple. I buy what I want, when I want it, at the time I am ready to buy. My priorities are clear, too. No automatics, and a decent level of performance. My '04 has served quite well in those categories.

jpgayan

Southernboy: Very well put. It really annoys me when people throw out the, "well then you shouldn't have bought a TL" nonsense. The TL is a great car but like anything, it's not perfect. That being said, it IS perfect for my needs and my budget right now. I'm very much sold on the sport sedan format with its combination of room, acceleration, handling, and fuel economy. Sadly, it's getting tougher and tougher to find a reasonably priced sport sedan with a manual transmission these days. I wish Honda had offered the Accord sedan with the V6 and 6mt. It's not pretty but it would have better met my needs with more back seat room. It's embarrassing to put people over about 5'11" in the back seat with how much the moonroof encroaches on head room. Sorry, got off track. Fuel economy was a deciding factor in getting my TL instead of a G35, as well as front wheel drive for winter months despite the almost dangerous levels of torque steer.

SouthernBoy

You got that right. Next time out, I'm not sure what I'm going to do. Like you, I really do like nice performance sports sedans but as you said, ones with manuals are going to be harder and harder to find (think virgin at a frat party). I am leaning towards the new Mustang with the coyote V8 engine so perhaps that's the way I'll go when the time comes.

IDM

very good stuff thank you guys!

1995hoo

The Belt Parkway could almost be worse than the streets depending on the time! The thing about city traffic, especially in New York with all the double-parking and such that can make it hard to get it out of second gear depending on where you are, is that it kills the fuel economy in the TL. I've averaged 30 mpg at average speeds of 70 mph on long highway runs, but I've had some tanks where doing all city driving I averaged 18 mpg when the traffic was horrendous several days in a row. Bear in mind that when you're idling at a red light or sitting in stopped traffic you're averaging 0 mpg.

(Regarding New York, I've lived in Virginia since I was a little kid, but most of my relatives on my mother's side lived on 91 Street in Bay Ridge until about eight years ago. One aunt on that side now lives at Breezy Point and the other lives at Roxbury; one cousin remains in Bay Ridge. My father's mother, who died in 1995, lived in Bay Ridge but moved to Far Rockaway in the early 1980s and lived there until she died.)

Hondaforlife954

I have been driving my car alot. This is prob 30-35%city and 65-70% highway driving and under normal driving conditions. Was not trying to make baby it in any way. i did change my spark plugs and air filter at the beginning of this trip log.

08-TL-s now at 58,200miles with snow tires on. 33-35psi front 30-32psi rear. Depends on temp.



cheers!

Hondaforlife954

Did i mention i live above 5,280 feet! when i was headed home it drop to 28mpg.... when i filled up calculated is about 28.6mpg.

KiWiLiT43

Are you sure about that? I watched a Myth-Busters gas mileage episode too; and I seem to remember them proving that over 55 Mph that having the windows down did burn more fuel than running the AC at the same speed. But that below 55 Mph the difference was negligible.

Not calling you a liar, but that was what I seem to remember from that episode.

TheWeez

-avg 26mpg mixed winter with winter tires, +28mpg summer with summer tires
-manual
-'03 CL-S
-91-93 octane
-Minneapolis
-temp -20º - +100º
-70% highway 30% city
-mods K&N filter

I almost always shift 1-3-5-6. I've gotten as high as 37mpg from an entire tank one a road trip from Wisconsin back to Minneapolis. Average speed was just a bit under 80mph.

The government has a great site where you can track your mileage for free. I wish more people with my car would sign up because you can share your data and see it up against others with the same car so it'd be nice to have a larger sample size. I've been keeping track of mine on there for about 4 years.

https://www.fueleconomy.gov/mpg/MPG.do

TheWeez

I believe you are correct sir. Below 55mph is was negligible. Just the same as a dirty car vs a clean one unless you're talking caked with pounds of dried on mud instead of a light dusting of dirt like most cars get.

ashdec87

Best way to get good gas mileage is to follow a truck when on long trips. I've done that for short distances and was showing 40+mpg.

deantl

Please list:

-24MPG
-auto
-year 2008
-premium of course
-new jersey
-currently 60-80 degrees
-Currently 23 @ city driving. Was getting an avg of 27 on a 70 mile trip from PA to NJ on I78 staying at a good 70-75 and only a few "slip ups" to 90 or so. The other day on a slower paced highway I was doing 65 and was getting 31-34AVG.

deantl

HA I am glad I saw this, have tried a few times and is true.