Fuel Consumption

I had a '98 Jetta TDI which averaged about 60 mpg. My new one, a '99 jetta, old body style on a recent trip of 2,375 miles only offered up 46 mpg. Quite a difference. Both cars ran the tri in the same time of year, January in eastern Canada and both had winter snows all round.
Cruise control was used 90% of the time at 119kms/hr or about 75 mph.

Any thoughts on this variance ?

wind direction? hauling to much crap in the trunk?

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Blk/Blk Debadged 2000 Golf GL TDI

Engine still needs to be broken in probably. VW uses high durability chomoly piston rings, i think...so break it takes a little longer..

Im at 10,000 miles now and mileage is improving still. I average about 49-50 in mixed driving and 52 highway. But I drive fast all the time..

99TDI: The 46 MPG sounds accurate and believable, especially if the engine is still breaking in.

Did you get 60 (or near) MPG for more than one tankful in your '98?? I find that number extremely hard to believe. If your answer is no, then a simple miscalculation resulted in that number.

In 70,000 mile on my '98 Jetta TDI, the highest I EVER got was 54.5 MPG, and that was under the most ideal conditions.

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Ric Woodruff

Braumeister von Sehr Gutem Bier
Since the Last Millennium

1998 Jetta TDI Sport

Those would be imperial gallons, Ric. He's in Canada.

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Always interested in steep & deep.
And now, a few great weeks of spring skiing...

Hehe, that's right PH. It is important to take notice of the units - we don't want another mission to Mars foiled by units conversion again.

There is no such thing as imperial gallons anymore, since all the countries that used to use it have gone metric.

Canada has also gone metric, and I assume he did the conversion from metric (liters) to U.S. gallons.

If he didn't, then 46 MPG (imperial) is poor fuel economy & something is not kosher.

My 1.8 kg. (4 lb.) can of beer mix makes 5 imperial gallons/ 6 U.S. gallons, so 5/6 is the conversion factor.

5/6 x 46 = 38 MPG. That's aweful if true.

[This message has been edited by Ric Woodruff (edited April 17, 2000).]

Gallon:

A unit of volume in the U.S. Customary System, used in liquid measure, equal to 4 quarts (3.785 liters).
A unit of volume in the British Imperial System, used in liquid and dry measure, equal to 4 quarts (4.546 liters).

Back to the original question: There seems to be quite a bit of inexplicable difference between one car and the next.

Some Passat owners report 1600 or even 1700 km on a tank. Normand just started a thread describing this, and Jon Bartlett has been up there, too. But in my case, the needle is just touching the red marks on the gauge around 1200 - 1250 km, and the fill-up is about 62 litres from that point (including some "venting"). The best I've ever done was 4.9 L/100 km, and that was basically constant 110 km/h driving. Barring extraordinary things like driving 80 km/h all the time, I think this is about the best it will ever do. (But it's good enough to keep me happy...)

So I don't know. Some engines seem to work better than others. Why? Beats me!

Brian P.
'96 Passat TDI

3.785/4.546*6=4.995601. Close enough to 5.00 for me. :

The Golf, Jetta, (& NB?) have 14.5 gallon nominal tanks, while the Passat is 18+ gallons nominal tank. That explains some differences

Ric

Doesn't explain why one Passat does 1200 km to a tank and another does 1600 km!

Brian P.
'96 Passat TDI

GoFaster,
I think the old Passat has a 70 liter tank - so with venting and all you should be able to squeeze in much much more than 62 litres, which in fact is the amount you get into a new Passat.
Check for indentions in the tank, maybe it got less quantity that way.

ThinkDiesel...

How fast you driving?

I noticed on my last tank that my mileage dropped a large amount.. I was cruising at 85-90 from Houston to Beaumont and back for the past 2 days... I was at about 40 MPG.. I suspect that my last fill up was incomplete due to foaming..

I normally get about 48mpg of cruising around 70-75 80% of the time and being in town the rest...

In response to some of your comments. At the time of the trip, the car already had 70,000Kms or 43,750 miles on it. I am a highway driver, cruising approximately 300kms/day to work and back. Conversion is 5/8 therefore, (kilometers X 5 = X)and X/8 = miles.

1 litre = 0.22 Imp gal. That kms/ltr means nothing to me, I'm too old. Based on this, My tank is approx. 12.1 Imp.gal.