Bad mileage ?

RikAmirnov

Banned
Joined
Oct 26, 2012
Location
Ontario
TDI
98 Käfer
Im getting roughly 34 MPG[800km/55L] ( city/hwy combo) why so bad ?

99.5 ALH MT

regular service no CEL, Fresh new intake, tuned, no EGR, Nice tyres,

any advice ?
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
How much of each city / highway? Does the engine get up to temp? First time going into winter with a TDI?
 

RikAmirnov

Banned
Joined
Oct 26, 2012
Location
Ontario
TDI
98 Käfer
First official winter,

I let it warm up 10mins before going anywhere unless its warm from a previous drive,

60/40 city/hwy and when its on the highway no more than 75km at a time
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
First official winter,

I let it warm up 10mins before going anywhere unless its warm from a previous drive,

60/40 city/hwy and when its on the highway no more than 75km at a time
What MPG were you getting before?

TDIs get less MPG in cooler weather. There's no need to idle, startup, wait a minute or so and drive gently until it's warm. I assume in your city driving the engine gets up to temp? How many minutes or km of city driving each day?
 

RikAmirnov

Banned
Joined
Oct 26, 2012
Location
Ontario
TDI
98 Käfer
I am has removed the vent , but i pour slowly and wait for the foam ( if any) to go away

fuel consumption number of Litres filled /KM driven ( from ODO)

Timing is retarded , as for previous consumption about the same but it was before my overhaul filters,intakes, tuning...

until 3/4 tank i get 350km after 850km once light turns on
 

jay_fyp

Veteran Member
Joined
Oct 29, 2004
Location
New Jersey
TDI
2015 Golf TDI 6MT 2004 Jetta TDI (PD) 5mt R.I.P - 2013 Golf TDI 6mt - 2004 Golf TDI (PD) 5MT
Get a frostheater, you'll have close to operating temperature right when you start the car. This greatly improves your mpgs in the winter especially and even can be used in the summer. I installed one a few days ago and the mpg gain was/is significant.
 

mrcowden

Well-known member
Joined
Aug 17, 2011
Location
Downers Grove, IL
TDI
2011 Golf 4D, 6MT
Get a frostheater, you'll have close to operating temperature right when you start the car. This greatly improves your mpgs in the winter especially and even can be used in the summer. I installed one a few days ago and the mpg gain was/is significant.
^^^ +1 What jay_fyp said. ^^^

When I plug in my FrostHeater, I get mileage very close to the summer numbers. Without it, I'm usually down about 10-18% depending on how far I drive. Thinking of adding an oil pan heater so it has plenty of oil flow at cold starts as well.
 

MichaelB

Veteran Member
Joined
Aug 11, 2009
Location
SE Wisconsin
TDI
2014 Passat SE DSG
[QUOTE Thinking of adding an oil pan heater so it has plenty of oil flow at cold starts as well.[/QUOTE]

You are probably using a full synthetic oil I hope. Don't worry about oil flow from cold starts unless you live in Antarctica.
 

naturist

Veteran Member
Joined
Apr 2, 2001
Location
Bro Jerry's hometown, Virginia
TDI
2001 Jetta TDI, 2005 Jeep Libby CRD, 2012 BMW X5 35d
#1, letting it warm up for 10 minutes before driving is part of the problem, not part of the solution. Firstly, it won't warm up much at all just sitting there idling, and second, you are getting ZERO Km per liter, aka infinite liters per 100 Km while it is sitting there idling.

#2, you are no on winter diesel, which is going to increase your liters/100 Km usage by about 10% all by itself.

#3, city usage is hard on the fuel usage. Diesels are best cruising for long distances.

#3b, city usage involves time spent in low gears, sitting at traffic lights, and applying the brakes frequently, all of which waste fuel. Which is why city is hard on fuel usage.

#4, do you make many short trips? Doing so also kills fuel usage because the engine and driveline do not get a chance to heat up properly. During the cold drive, it uses more fuel. Another reason longer drives are better.
 

BlankThis

Veteran Member
Joined
Nov 23, 2012
Location
Montreal, QC
TDI
2002 Golf GLS TDI
How hard have you been driving? Diesels are great that you can drive them hard and still get great mileage but if you always have your foot in it, your numbers will drop.
 
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