Why don't TDI's like winter

[chef73]

I have a 2010 Jetta Sportswagen and it barely gets in the 30 range during the winter is there anything i can do to improve the gas mileage for the winter like using a fuel additive

[Offroad_TDI_Guy]

Originally Posted by chef73

I have a 2010 Jetta Sportswagen and it barely gets in the 30 range during the winter is there anything i can do to improve the gas mileage for the winter like using a fuel additive

Get an air intake to let that baby breathe. That could help a little...

[Derrel H Green]

Originally Posted by chef73

I have a 2010 Jetta Sportswagen and it barely gets in the 30 range during the winter.
Is there anything I can do to improve the gas mileage for the winter like using an fuel additive

No additive will take the place of warmer weather.
Ours simply does not get good F E when it is colder either.
As the temperatures drops, so does my F E bigtime.

Last week, we saw 80 degrees F. here, and on my 125 mile R/T,
it got almost the same F E as it does during the summer.

During the more or less normal 50s to 60s here in the winter in the daytime, ours simply
will not do nearly as well! Couple that with the winterized fuel for which we must
shell out $3.70 or more, we simply can not win, can we?

Anything you could do to get the motor to warm up more quickly and run warmer should help.
How about doing away with the cold air intake? Make it gulp in warmer underhood air instead.

I think I'll try that. What do you think?



D

[Plus 3 Golfer]

Originally Posted by chef73

I have a 2010 Jetta Sportswagen and it barely gets in the 30 range during the winter is there anything i can do to improve the gas mileage for the winter like using a fuel additive

Forget the air intake. Your "baby" breathes fine. There's really not much you can do but get the car to warm up faster. This must be your first diesel: speak in terms of fuel ecomony, fuel mileage not "gas" mileage.

Like Derrel says, a TDI takes a long time to reach operating temperature in cold weather. Even in the Valley of the Sun, it takes my TDI about 7 miles at 45 mph before the temp gauge registers normal when the ambient temperature is in the 40s. At 7 miles my MFD average MPG is in the low 30s. My guess is the oil is still not up to operating temperature after 7 miles. It takes me about 15 miles before the average MPG climbs into the lower 40s. So, short trips in frigid weather will have a significant impact on MPG. My guess is that if your trips are short in duration you could easily see a 10 to 15% drop in fuel economy during Ohio winters.

Also, the winterized fuel in OH will probably cost you about 2-3% or so in MPG due to reduced energy content in winter vs summer fuel assuming the winter fuel is cut with kerosene.

[sprstu]

To help you get up to operating temp faster you can install a "frost heater". This is a system that heats and circulates your coolant while you car is off. By setting it up with a timer so it comes on an hour before you have drive really helps. You will get up to temp (and have warm air for our hands) much faster than without.

Another trick is to cover up your radiator with some cardboard or corrugated plastic board. This will help reduce the amount of cold air that flows across your radiator thus keeping your temp at the perfect running level.

Lastly, run for a while with the vent on recirculate to prevent frozen air from coming into your cabin and across your hvac system. This will help your car warm up as well as keeping you a bit toastier as well.

I live in Minneapolis so every winter we see a few weeks below 0, this year we had 37 days below zero, 20 of them in a row. I know what its like to run a TDI in the winter months, poor fuel and frozen temps kill your mpg.

[Cstdi]

holding the tranny in gear to maintain 2000RPM when you start it until you get up to temperature, will get you there much quicker in the cold weather

[Calidris96]

Okay, I'm sure I'm missing something. Living in Texas, we don't see a whole lot of sustained cold temperatures, so I've not notice this phenomenon. But colder air is denser which aids combustion. That's the whole point of a cold air-intake. Shouldn't colder ambient air temps result in improved fuel efficiency? What's happening here?

[chittychittybangbang]

Originally Posted by Calidris96

Okay, I'm sure I'm missing something. Living in Texas, we don't see a whole lot of sustained cold temperatures, so I've not notice this phenomenon. But colder air is denser which aids combustion. That's the whole point of a cold air-intake. Shouldn't colder ambient air temps result in improved fuel efficiency? What's happening here?

cold engine = thick oil, longer warm up (more emissions, looser engine), and winterized fuel.

[Calidris96]

I see. The cold affects more than just the intake air temp. Duh.

I'd have to assume that the main culprit is the winterized fuel. Unless your commute is very short and all your driving is on a cold engine, I wouldn't think the 10-15 minutes it takes to get up to normal operating temp would have a great impact on overall mpg. Wish I had a commute that short...

[Cogen Man]

Originally Posted by sprstu

To help you get up to operating temp faster you can install a "frost heater". This is a system that heats and circulates your coolant while you car is off. By setting it up with a timer so it comes on an hour before you have drive really helps. You will get up to temp (and have warm air for our hands) much faster than without.

Another trick is to cover up your radiator with some cardboard or corrugated plastic board. This will help reduce the amount of cold air that flows across your radiator thus keeping your temp at the perfect running level.

Lastly, run for a while with the vent on recirculate to prevent frozen air from coming into your cabin and across your hvac system. This will help your car warm up as well as keeping you a bit toastier as well.

I live in Minneapolis so every winter we see a few weeks below 0, this year we had 37 days below zero, 20 of them in a row. I know what its like to run a TDI in the winter months, poor fuel and frozen temps kill your mpg.

Above is what I have done this past winter. It does help with warm-up time.

Originally Posted by Cstdi

holding the tranny in gear to maintain 2000RPM when you start it until you get up to temperature, will get you there much quicker in the cold weather

Also a good suggestion. On a really cold day with a stone cold engine start I'll drive in either Sport mode or Tiptronic I think it's called and shift up and down myself to keep the rpms up. I just don't do any Italian tune-ups until she's nice and toasty.