It's All In The Tune Up

[Jack Meoff]

This was a bit hard for even me to believe but....
I'm borderline anal when it comes to how well my cars are running.....okay is unacceptable.

I'm on top of maintenance and all three are tuned to pass the "beer bottle air cleaner test".....I can sit a beer on the air cleaner with it idling and the bottle barely moves...

I believe this is why I was flabbergasted when I figured out my gas mileage lately....were in Canuckland so everything is metric up here but basically....I went to my trailer which is roughly 250 kilometers away, drove all weekend up there, then came back three towns towards home.....I pulled into the only Shell up there to fill up.

Started pumping and shortly after the nozzle pops signifying that I'm full....I look at the total.....$25!!!! @ $1.49 per liter!!!
That's insane....
I did the conversion and it works out to roughly 33 mpg on a 27 year old car shaped like a brick with a cast iron 5.2 liter V8!!!

Unbelievable!! I'm going up again tomorrow and will see if I get those results again.....

Jam your yaris....I'm taking the Fifth!!!

 

[Yellowdart69]

My 318's usually ran just over 30MPG , on the highway, back when I used to keep track of those things. Oh - for our American friends, the Imperial gallon is larger than the American gallon!

 

[Jack Meoff]

That's true....our gallon is larger....
I used the yankee gallon in my calculation.....and I don't really keep track of such things either.....but I was curious.

Not bad at all for a stock 27 year old car with the aerodynamics of a brick.

 

[brotherGood]

I was gonna say..30MPG on a smog 318, that's a little nuts. Especially for being stock.

 

[kkritsilas]

Imperial Gallon is 160 Ounces. US gallon is 128 Ounces. Imperial gallon is bigger by 25%.

To get MPG (Imperial GallonS) the equation is 282/(Litres/100 Km). I think the US gallon conversion rate is 240/(Litres/100 Km).


For $25 in gas, you got 16.8 L. 16.8L consumed over 250 Km means your metric fuel consumption was 6.7 L/100 Km. That would give you about 42 MPG per imperial gallon. . In US gallons, that is about 36 MPG. Something doesn't look right. You were either going down hill (i.e, on a long shallow decline), or you had a serious tail wind.

In my old Lincoln Mark VIII, I used to travel to Crow's Nest Pass, which is 2.5 hours south and west of Calgary. The area is known for having some of the highest winds in Alberta, as the wind comes down the Rocky Mountian passes. On one trip, I got 7L/100 Km (roughly 40 MPG Imperial). Another time, I got 20 L/100 Km (14 MPG Imperial), same speed set on the cruise control. Difference was the wind, with the tail wind, mileage was sky high, with a headwind, mileage dropped like a rock. This area is an extreme example, though. A typical day has 50 Km/H (30 MPH) winds, and the locals don't even notice. They only start to take note at 80 Km/H (almost 50 MPH). Because the wind speeds are so high, and blow all the time, everything leans to the east, as the winds come from the west towards the east, mostly. This includes houses, commercial buildings and trees.

Kostas

 

[Jack Meoff]

Kostas....

I agree with your theory on head or tail wind.
The car is basically a brick as far as aerodynamics. No downhill though....flat pretty much all the way.

But the math stands on that particular run.
I'm going up to my trailer this afternoon and I'll do the same experiment and see how it does this time...

I was shocked myself when the pump popped at $25.
We will see how the mighty fuel efficient Fifth does this time.

 

[Jack Meoff]

I was gonna say..30MPG on a smog 318, that's a little nuts. Especially for being stock.

33 actually...
It's true though.....my numbers don't lie.
For the record she is running beautifully...
We'll see what the numbers say this weekend.

 

[Monkeyed]

33 actually...
It's true though.....my numbers don't lie.
For the record she is running beautifully...
We'll see what the numbers say this weekend.

DANG! See if you can walk on water while you're there, or at least turn it into wine!!

 

[Jack Meoff]

DANG! See if you can walk on water while you're there, or at least turn it into wine!!

Or beer!!
We'll see how she does this time.

 

[jasperjacko]

I have seen many pumps shut off early, and the car still take several more gallons. Who knows though, maybe you have discovered the holy grail of mpg!lol

 

[Jack Meoff]

I have seen many pumps shut off early, and the car still take several more gallons. Who knows though, maybe you have discovered the holy grail of mpg!lol

I hit the pump again figuring the same thing but it immediately popped again.
I started the car and the gauge pinned to full...
I dunno.....we'll see how it does this time....

 

[Jack Meoff]

Well Kostas.....your brick aerodynamics observation was correct.
Had major head wind on the way up and the best I got was 21 mpg...

 

[Monkeyed]

Well Kostas.....your brick aerodynamics observation was correct.
Had major head wind on the way up and the best I got was 21 mpg...

still, that's about double what I get

 

[Jack Meoff]

still, that's about double what I get

Really??
Strange...you running the stock lean burn setup?

 

[Monkeyed]

Really??
Strange...you running the stock lean burn setup?

ayup, 2bbl and all. cleaned rebuilt the carb, new plugs, wires, cap/rotor, o2 sensor. she runs MILES better than she did when I got her, but still a little off. none of that made any difference in the mpg. have been debating the expense of replacing the ecu, vs. a conversion.

 

[Jack Meoff]

ayup, 2bbl and all. cleaned rebuilt the carb, new plugs, wires, cap/rotor, o2 sensor. she runs MILES better than she did when I got her, but still a little off. none of that made any difference in the mpg. have been debating the expense of replacing the ecu, vs. a conversion.

Did all that myself with probably the same results.
The big diff came when I swapped from the Champion plugs to NGK ZFR5N's AND (and it's a big and) started running non ethanol premium which in my opinion more than pays for itself both in mileage and overall driveability..
I also (after the gas change) advanced the timing just before pinging which was a fair bit because of the better gas.
That resulted in a perkier performance.

Just a note....the NGK's sit a little deeper...the theory being they sit better into the chamber causing better combustion.

All these things together has definitely made a big difference.
And I should note that on NoCar's recommendation I've been adding Lucas fuel treatment every third or fourth tankful.
That has also helped......

 

[alf44]

my old 85 5th 318, no cruise control, 266.000 miles and not tuned to a knats eyebrow. got over 20 mpg most of the time. i only get 20 -24 on a average day with my super /6

 

[ramenth]

Not just speed or tail winds, but taking into account the way you drive can account for a lot of variations. We caravaned to Florida and back one time. Mom and Dad in Pop's '72 Duster, my sister, her ex and the kids in his '76 slant powered Volare, and my brother and I bringing up the rear in the F250.

Pop picked up some bad gas in the Duster on one of the fill ups and was fighting gas starvation from northern GA through the Carolinas. Finally he pulled into a small town with a truck stop and wound up pulling the tank. Full of rat's nest. The rest of the trip home Pop babied the car, keeping us around 55 the whole way. My sister's ex saw an average the rest of the trip at 34 mpg's with the 833OD backing up the slant. He was never able to duplicate that for the rest of the time he owned the car. Best he saw was mid to high 20's.

I credit the good gas mileage to playing tail to Pop.

 

[Jack Meoff]

I used to be a total leadfoot but I guess I've mellowed with age.
Mind you my average speed on the way up north is 60-65.
I guess if I shaved 5-10 off of that I'd get better mileage.....
I'm guessing my overall average on the highway is around 22-25 mpg which for that car I consider pretty descent...