sauceman

A few weeks ago I had posted that I had travelled 1094Km with a single tank. It was worth 43mpg/36 US mpg.

Well, I just lasted this last single fill for 1056Km, slightly lower, but I wasn't trying to get a good mileage until I realized this morning when I had 700km that I still had gas for another 300+ Km. Still, I got 41mpg / 34.2Mpg US.

And that was with... 73litres. (I know some of you still don't believe me, but hey, that's how it is anyway)

larchmont

I believe you totally. I've gotten similar numbers -- not for quite so long a stretch, but yeah.

tehCOW

you must have a lot of highway miles. How fast do you drive on the highway? those are numbers. The only time i ever saw those numbers was when i drove my civic. Keep up the good milage. I just filled up the other day 13gallons @ $2.34. I got 22 mpg, i've been bad.

dom

God damn I find that very hard to believe sauceman. I'm not saying I don't belive you, but Holy crap. When I travel all highway the best I did was like 700km. Your saying 1056km

Maybe your car is special?

KC 2004 TSX

With the 2 tanks I have ran through my TSX I log 90% city miles and still got 24 mpg.

sauceman

And the thing is, Domn, theoretically, you should be able to get even better mileages since you have the 5AT.

But I do drive very moderately, at around 65mph on the highway, and driving beyond 1000km on a single tank requires that you drive around 90% highway. So it doesn't happen very often that I can get that sort of performance, because the fill lasts me for a few days, and I don't usually drive 90%+ of highway. It's more like 60% highway / 40% urban.

dom

My two long highway drivers were both with 4 people in the car and with the AC on 90% of the time. Maybe thats had an effect on mileage. But I thought my 700km was great.

I'm getting 26-27MPG in 80 City/ 20 Hwy now. I take it your in the car alone and the AC's off?

I'll have to try a long trip with no AC and only 2 people in the car.

KC 2004 TSX

You use A/C in Toronto?

larchmont

Don't worry at all about the A/C -- it makes very, very little difference in this car.

dom

We'll see who's laughing when your getting your butt kicked by a Canadian in the NFL pool

Larch, I thought AC does'nt have much of an effect as my city numbers are always pretty identical with or without it on. But seeing 1000km+ makes me question that?

wiz

How many miles is 1000km? I've gotten 33.6 MPG in my TSX on my trip home from Cleveland once...all highway driving at about 65-75 MPH

dom

1000 / 1.6 = 625 Miles (I think)

sauceman

Yes. And 1056Km was 660 miles.

Domn, I usually am alone, but with the trunk full of work stuff. And as soon as it is more than 20°C outside, I usually use the A/C, so yes, I have been relying a lot on the A/C.

sauceman

I'll try and make a comparison some time for you, Larch. I'd say about a 5-7% difference.

larchmont

Maybe. But I'd bet less.

For sure, it's less than most of us ever thought.

lshenretty

I'm sure larch is right about this. Seems like there may be something about this elsewhere on the board.

My guess is rolling the windows down produces a LOT of drag, maybe even more than the AC compressor. My Saab 9000 was like that - actually did better with the windows up and the AC on - and that car wasn't nearly as slippery as the TSX.

I suppose if you can get by just tilting the sunroof up you'll do better than with AC.

larchmont

And they say we might have nothing to talk about when there's no news!

Good point -- When we talk about whether the A/C makes a difference, COMPARED TO WHAT? Compared to no A/C but with the windows open, or compared to no A/C but with the windows closed (which usually doesn't happen, not in those conditions anyway)?

THAT probably makes a big difference.

sauceman

Good point. I want to compare AC on and off, both with windows closed. I too believe it is much worst with windows open, the car becomes a parachute. Maybe the tilt sunroof would be a good solution, but even then...

MikeL

Congratulations!

My question is this: How did you put 72 litres in the tank? If I'm not mistaken the tank is rated at 60 something. Do you have special top of techniques or have you discovered a secret compartment?

An even bigger question is, where did you find the courage to use up all 70 litres? Usually when the light comes on and 100 or so km have passed I'm already sweating bullets!

Good, inspirational news though, especially in these days of high gas prices (just paid over $1.00 a litre for the first time!).

sauceman

You will easily fill your tank up to 60-62 litres when you're really dry. Then, if you draw back the nozzle until you see the tip of it, and pour very gently some more gas in, you will be able to add some 10 extra litres.

I think this is because there is a chamber for gas expansion. This happens because it is always much cooler in the gas station's tank then the air temperature. So once it's in your gas tank, it will heat up and expand, and create a lot of pressure, and even fill. So you got this chamber to block all spills and gas vapours, but you can fill it up. DO NOT FILL IT UP ALL THE WAY LIKE I DO UNLESS YOU ARE IMMEDIATELY TAKING OFF TO DRIVE FOR A DISTANCE OF OVER 100KM. Otherwise, you may have problems.

When you immediately drive after, you burn gas as fast as it expands, so basically, you almost drive for 100km for free. If the temperature difference is great, it may even be more.

And I know this way of filling up the car completely invalidates gas stations' anti-emission systems, but it doesn't wreck them.

Also, to answer your question, since I drive a lot, I get to understand the fuel gauge's pattern pretty well. I know when it's time to stop, usually to about ½ a litre before sputtering out. Today I drove with the empty gas light on for 232Km.

But it doesn't mean each car is calibrated the same. Even on my old 95 EX Accord, when it was newer, I would be able to drive for 80Km with the light on, and in the end, I would be able to drive for only about 30 Km, so the gauge eventually might change in "performance" and catch you off your guards. But the best remedy is always (at least in my case), to have a little red 5L cannister filled with gas. You'll have an extra 50-60km of gas in there in case you run out.

TSXautoXer

36mpg?!?!?!?! I'll be damned....the best I got so far is just close to 20mpg!!! I really gotta start learning some fuel saving driving technique...

dom

Interesting, even trying your technique, which I do every time I fill up I can only fit at most 55L of gas. And I get about 550 to 600km with that. The tank is 65L, So I figured no more would go?

AKay

damm right now im only getting about 24 mpg. Will this improve once the engine is broken in?
AKay

sauceman

Then it means you can drive on a lot longer before running out of gas.

kuraki502

hey sauceman, what are your tire pressures at? i want those mileage too!!!

sauceman

I don't know. I didn't bother checking. I think the dealer does that verification with the service, but otherwise I couldn't tell.

Speed Demon

Wouldn't it be funny if the tire pressure (PSI) directly correlated with best highway MPG?

36 PSI = 36 mpg (overinflated)
32 PSI = 32 mpg (normal)
26 PSI = 26 mpg (underinflated)

etc.

Bear Trap

That doesn't make any sense. Gasoline is a liquid and has very little volume change for a given temperature change in a closed container (otherwise it evaporates and looses volume). What you are saying is that traveling at 100km/hr, consuming 2 liters for the first hour, you could stop to fill up and not be able to put any gas in because the level in your gas tank is constant because the gas expanded this much. I don't buy it.

Not that I don't believe > 30 mpg is possible, I know it is. Hell, I got 32 mpg on a trip with my CLS. So I'm sure 35 is possible for us, but this is not the reason.

sauceman

No I'm not saying it is THE reason. I think it helps, but only at great temperature changes, like over 20°C.

It is mostly because I make a point of driving smoothly, that I get the good mileages. But that don't mean I don't drive the shit out of my car sometimes, but I save that for the weekend spins.

sauceman

Bringing this thread back to life!

I just did my second best mileage, but not in summer. 1101km with 72.5L.

This means 35.9mpg

Average weather was sunny and dry in the first 500km, then wet and with a front wind of about 20-30kph for the remaining trip.

Temperatures were between 4 and 13°C.

I find it interesting that I'm now being able to reach those mileages in cooler weathers. I used to be able to do it only in 20°C + weathers.

But here's the real kicker: Octane of gas used was 87.

And my questions are: Granted, 87 octane imposes a decrease in performance. Very noticeable if you ask me. But does it really decrease fuel mileage? My latest experience tends to show it isn't so.

Also, where did we get the info that fuel mileage would be worst with 87? I can't seem to remember Honda ever saying something about this.

I guess I'll try and look into this further.

CGTSX2004

iTrader: (1)

My guess with 87 octane decreasing performance is actually more related to the driver than the car itself. If a driver expects a certain level of acceleration and the 87 octane reduces engine performance, the driver will tend to rev the engine higher to attain the same level of performance, thus consuming more fuel. However, inherently, the engine itself does not consume more fuel since using 87 octane should not significantly change the actual air/fuel mixture itself.

But that's just my theory.

sauceman

I'm thinking more or less along those lines too.

When the ECU "hears" knock, it will retard cam and fire. It doesn't necessarily mean the amount of fuel injected is increased. Just that it is detonated with less efficiency. But if, by cruising at 55mph, that extra efficiency isn't needed anyway, then it all cancels down. Right? Wrong?

Belzebutt

Sauceman I have to ask, since you travel so much, how do you find the time to moderate this board? Do you post from the road, getting internet access in every hotel you visit?

sauceman

I'm an addict to this place, so I find the time!

I'm back home every night, except for a round trip every 3 months.

I usually do the moderating stuff early in the morning, then leave for work.

But days like today, I took it off. Last week and weekend were exhausting, so today was dedicated to resting.

tsxhondatuner

damn gas is like $2.89 here i just reliazed it.

dom

Holy Thread resurrection Batman

Sauce, why the 87 Octane