Help for poor milage during winter cold ??

Since the TDI engines' performance is affected by heat (or the lack of it in winter). Doesn't it stand to reason that the intercooler's purpose is only needed above a "certain" temperature and might even be a contributing factor to the poor fuel economy during really cold conditions?

Also, as some of you probably have noticed, the "big rigs" use a device on the grill and/or radiator that restricts air flow to aid in quick warm-up and maintaining of a more constant engine temperture.

With the above in mind:

Would it be benefitial to cover the intercooler during the winter months?

What about the radiator? This could be an engine destroying move if not done properly!

What's your thoughts and experiences?

Cover the Grill openings that lead to the rad, but not the Intercooler!! I have had the rad blocked since mid November here in Ontario, and no issues with temp going over 90 C and have not heard the fan going what so ever. Leave the intercooler air flow open as this will help in the combustion as cool dense air will compress better!!

I used some foam pipe insulation to block incoming cold air. The engine warmed up noticibly faster. MPG's seemed a bit improved as well.

I read a members post whom suggested blocking the grill would reduce aerodynamic drag. Something I'd not thought of before but seems logical. Less air going through the grill exiting under the car would seem to be a drag reducer.

I can't imagine it ever getting cold enough in Kentucky to want to totally block off the grill. On the other hand I'd imagine we could block some air off right up to air conditioning season. Keeping in mind that excessive heat can be a real killer on under hood components like batteries and alternators. I don't hear to well and never hear the radiator fan run.

The complexities of controlling airflow manually or mechanically is why it's not standard equipment.

More than likely your mileage hit is a result of winterized fuel, which is my biggest problem.

As for cold, you might look at a TDI heater, to start your engine already warm. That is when your biggest mileage hit occurs, for the first 10 miles your mileage is less than 25MPG or there about.

One of my best tanks was 58 MPG, driving across Kansas in July, (at night, in the rain, doing about 80.)
Though my worst have been during the winter in really bitter cold, (38 MPG when it was 10 for almost 2 weeks)

In southern California I use a 50% cardboard winterfront in the winter. I use heat up rate and peak temperature as criteria for the winterfront being on or off. Have you noticed that Freightliners (and various others) have ~10 square feet of radiator but its not unusual to see a 1 square foot or 10% winterfront on them even if its not that cold out? An engine heater doesn't make any sense effort wise, money wise, etc. in California and Kentucky is not that far south of Illinois but there are other gradations to be considered; such as oil heaters, battery heaters, etc. Of course some people don't have what it takes to use a winterfront, especially if the elevator doesn't go all the way to the top.

An engine heater doesn't make any sense effort wise, money wise, etc. in California and Kentucky...

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How about an EZHeater, from us.....perfect for warmer climates!

We can compare the TDI engine to a gas Honda Insight. I've owned both. The Insight guys block the radiator 100% off with cardboard or rubber mats etc etc, in the winter time. It was the only way the litte 1000cc - 1liter engine could put out great MPG in the winter time. Some Insight guys also use a warm air intake-- they simply suck air from the back of the engine near the ehaust heat.

The Golf was designed for gas engines 2.0, 1.8t and Vr6 cars along with many TDI from 90hp to 150hp. Other than on some vr6 and r32 cars the front bumber/air intake is the same. A diesel engine does not produce the same amount of heat as a Vr6 and does not need as much air flow.

Next point is the car was designed to operate in temps above 100 with A/C on and sitting in traffic. That is alot hotter than 50 degrees at 70mph not accounting for windchill.

I don't have time to leave my laptop in my car and run vagcom all the time. But I would be curious as to what outside temp does blocking the radaitor off become unsafe for the engine.

I have a kamie grille in my 01. So I can pull it forward and slip a small sheet of lexiglass on cold days. I had to remove my lower grilles to mount my Passport zr-3 and PIAA lights.

You are totally RIDICULUS. There would be no return on that investment, emission wise, dollar wise, effort wise, etc.

Fred,
Can we get rid of these snake oil peddlers pushing dope on people who don't want it? Obviously there is no motive to assist others. He's only looking to line his own pocket.

You have to also look at the tires. First off are you running winters? There's more resistance on these tires than all seasons. Second, is it cold? At -40 celsius your tire pressure will drop considerably (grade 3 science cold contract heat expand). You may need to adjust your tire pressure on a weekly basis to adjust for fluctuating temps. We went from -5 to -45 overnight, I had four very low tires.

Ouote: "I would be curious as to what outside temp does blocking the radaitor off become unsafe for the engine."

What is the heat up rate of your tdi in 70 degree weather? Does it take ~3 minutes or ~6 miles to warm up? Taking this out to say ~30 degree weather suggest that it should take ~4 minutes or ~8 miles to warm up. But you’re finding that its taking 20 minutes or a lot more miles before the temperature gauge even moves. What would this indicate to you?

Okay, now lets take the reverse. You have the radiator blocked off and you find that its now 50 degrees out and your tdi warms up in ~3 minutes or ~ 6 miles. This would be a very obvious clue that you want to reduce the winterfront.

This exercise suggest that there is not one critical temperature to use a winterfront and another, not to. It suggest that the environment you operate in would be a strong consideration. The size of the winterfront is still another consideration. For instance, you indicated that the Insights are using 100% winterfronts with no ill effects.

does anyone have pics of how they used pipe insulation to winterfront their vehicle? I would love to see them.

What is the heat up rate of your tdi in 70 degree weather? Does it take ~3 minutes or ~6 miles to warm up? Taking this out to say ~30 degree weather suggest that it should take ~4 minutes or ~8 miles to warm up. But you’re finding that its taking 20 minutes or a lot more miles before the temperature gauge even moves. What would this indicate to you?

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You have a thermostat that is stuck open! What is the prize that I won???

No, we don't get the consistant cold weather here in Southeast Ky as you folks do north of say the Ohio River. But, we do typically have several cold snaps each winter that the temps drop at or below Zero Fahrenheit. The cold can and does hang around several days at temps below 20 degrees Fahrenheit.

On my daily commute, I do no less than 84 miles. Some days, with on the job driving, I might do 250 miles. Therefore, the cold temps, winterized fuel, etc., all play hovac with my fuel economy!

Considering I don't feel safe with tire pressure above 36 psi (winter or summer), I was looking for other ways to improve the fuel economy in the winter months!

One segment of my drive takes me up and over a mountain (a hill to those in the west). I can/do coast "in gear" for over two miles. On mornings that the outside temp is at or below 20 degrees Fahrenheit, the heat guage actually drops off considerably by the time I reach the bottom of the over two mile coast...... The warm-up cycle sort of starts all over again.

RiceHeater, I believe you are being waaaaaaaaaaay too harsh.

The heaters (Red Golf TDI's included) are useful to some on this forum.

Eliminating cold starts at low ambient temperatures DOES improve economy and reduce emissions.

Would one ever recoup the costs involved? Probably not. But there are other benefits that are harder to put costs on. Reduced emissions? Always a good thing. Immediate cabin heat? Worth the money to some.

Don't cover up anything, ever heard of the thermostat. There is no coolant flowing threw the radiator when the engine is cold it won't warm up any faster with it covered. If you die and nobody reads your will stating that your covered your radiator somebody could melt the engine. Dan

Don't cover up anything, ever heard of the thermostat. There is no coolant flowing threw the radiator when the engine is cold it won't warm up any faster with it covered.

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Yes it will..... because covering the grill will reduce the ambient heat lost coming from the manifold, outside of the block, transmission, etc.

As a result of maintaining the ambient heat AROUND the engine and transmission the engine itself will warm up faster.

If it doesn't help keep the engine warmer... why do 99% of the highway tractors up here in Canada cover their radiators?

RiceHeater, I believe you are being waaaaaaaaaaay too harsh.

The heaters (Red Golf TDI's included) are useful to some on this forum.

Eliminating cold starts at low ambient temperatures DOES improve economy and reduce emissions.

Would one ever recoup the costs involved? Probably not. But there are other benefits that are harder to put costs on. Reduced emissions? Always a good thing. Immediate cabin heat? Worth the money to some.

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Don't forget increased engine longevity in cold climates!!