puzzling fuel economy!!

tomaz

Well-known member
Joined
Oct 7, 1999
Location
Brezovica, slovenia
Hi!

I am owner of golf TDI 110HP since june 1999 and am very pleased with the car.

But my fuel consumption is a bit strange, so read this:

first tankful 42mpg or 5.6 l/100km with AC on and with windsurfing rack on the roof
mainly non highway - non city

then some tanks around 44-45 mpg the same as above, rack, AC

on sept. 25th my girlfriend and I decided to go to Sweden (we are from Slovenia). The car at the start of the journey had around 5000 km.
First tank of the journey from Slovenia to Gottingen in Germany at speeds from 130 to 160 km/h, highway all the time, some climbing and descending in Austria, no AC: 5.0 l/100km or 47mpg
Second tank Gottingen - Malmo, highway all the time, no hills, same speed, no AC 5.14l/100 km or 46 mpg
Then the bad news:
third tank in Sweden, highway 90 to 110 km/h (they have speed limit
), no hills no AC: 5.44 l/100km or 43mpg
fourth tank: Germany and Austria back to Slovenia, same road, 130 to 160 km/h, no AC: 5.6 l/100 km or 42mpg.

It shows a significant drop in mpg. Ok we found out in Austria at the way back that tires were at 1.7 to 1.8 bar and they should be at least 1.9. Can this be the reason?
Another factor: outside temperature was around 17 degrees C when going to Sweden and around 7 degress C when returning. Could thi be it?

I have to say I had never used less then 5.0 l/100km even though you guys can get much lower. And I do not drive fast, nor push maximal accerelation. The AC now in Slovenia is not needed. Please tell me how to get lower!

Oh yeah I remembered one more thing: when driving in Lund (city in Sweden) from one part fo city to another it took me about 10 minutes and the warning light for ASR/ESP went on and lit all the way. But morning after that it all was normal and had no more porblems for next 2000 km.
 

jaydhall

Veteran Member
Joined
Apr 2, 1999
Location
Aurora Colorado
TDI
2012 Passat SE, 1999 NB, 1999.5 Jetta GLS, 2004 Jetta
When I went to Sweden the milage was lower also. I thought it might be 'winterized' diesel? Other than that, I am not sure.

Lower tire pressure will reduce the enconomy, for sure. I am not sure it would be that much.

As far as the speed limit goes, I told my Swedish friend the speed I was going in Sweden and he told me they would not just ticket me, but throw me in jail! I slowed down a bit after that!

How is your economy now? Has it returned?

Perhaps it was not diesel but class 1 beer? (At least they found a good use for it...)

Taler du svenska?
 

colinstone

Veteran Member
Joined
Jul 25, 1999
Location
Oxford, England
Tomaz, Looking at your figures I assume you are using US gallons for the mpg. If so I think your fuel consumption is not far off. My UK Golf IV GT TDI 110 bhp has averaged 54.02873672 imperial mpg or 5.354619706 l/100km over 20000 miles, corrected for 1.2% odometer error - under reading. This is in the middle of your fuel consumption averages and my driving has included high speed 130 - 170 kph dashes across Europe (Czech Republic to Oxford UK in 10 hours solo driving) and carrying ski boxes. If you are converting to imperial UK gallons and not the weedier US gallons, then there appears to be a problem. An easy imperial mpg to l/100 km conversion is that 5.3l/100km is the virtually same as 53 mpg (imperial). I have not worked out a US gall conversion.


------------------
MY2000 UK Golf IV GT TDI 110 bhp plus TuningBox
- Me
MY1998 UK Golf IV GT TDI
110 bhp - Mrs S
MY1986 Golf II (petrol!)
 

ENUTPEN8

Veteran Member
Joined
Jul 31, 1999
Location
AR , USA
Tomaz, I suspect jaydhall is correct in pinpointing the culprit as winter diesel. My worst mileage on our New England trip came from winterized stuff we got in Connecticut (42 mpg with automatic, driving under 75 mph). Or it could be an insidious plot by the socialistic Swedes, fueled by a vast left-wing conspiracy...? Driveon...Nick at Night

------------------
'71 Super Beetle w/Hurst & header; '99 New Golf GLS TDI auto.
 

tomaz

Well-known member
Joined
Oct 7, 1999
Location
Brezovica, slovenia
Ok it might be Swedish diesel for the third tank, but the fourth was solely from German's Dea gas station. Second tank was from Shell in Germany and mpg were high!
Do you think they winterized diesel just the week we were in Lund (Sweden).

Just to cool down my anger due to low tyre pressure I went to gas station and pumped the tires to 2.0 bar! I guess it is not to much. Is it?
 
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