cold weather radiator wind block ideas?

BVCRD · **Posted:** Sat Feb 17, 2007 9:37 am

CATCRD wrote:

BVCRD wrote:

My temp gauge goes up to half way whether it is -15 or +90. I don't have a need for them. Most of the time, we are cranking the heat back because we are too hot. How cold is it where you guys are that you need this?

Halfway on the gage does not always mean the same temp. The needle is computer controlled to point straight up when the coolant temp is within a certain range, so as not to freak out the average driver. With a diesel engine, you will generally get better fuel economy by running the cylinder head slightly hotter, within reason.

Thanks. That's good to know. We have a heated garage, so probably helps warm up time, but we are still toasty going down the road with the heat set on about half max.

RFCRD · **Posted:** Sat Feb 17, 2007 11:54 am

BVCRD wrote:

My temp gauge goes up to half way whether it is -15 or +90. I don't have a need for them. Most of the time, we are cranking the heat back because we are too hot. How cold is it where you guys are that you need this?

Just a few cold weather observations from working around heavy vehicle diesels:

1). It is very common to over-chill charged air in cold weather. In general, colder & denser charged air make it possible to burn more fuel and produce more power. I have seen this on buses where you can get a noticable bump in power (and some black smoke) in cold weather. The fuel consumption will also increase by a good 15-20%, no different than my CRD experience over two winters.

2). At all times, the ECM is trying to achieve optimum water temp (193*F according to DDC research from the mid 90's). Water temp get too high or too low, the ECM adjusts the injector pulse & fuel delivery until it reaches optimum. One of the reasons for the drop in fuel economy is the ECM will feed more fuel to engine in an attempt to maintain optimum temperature. A strong clue that this programming is being used is DC's choice to use a viscious water heater.

3). You don't see many winter fronts today because most big trucks & buses have temperature controlled shutter to block the airflow along with clutched fans. A typical OTR bus will have 190* thermostats, 195* shutter-stats controlling the air shutters and 200*+ stats controlling the radiator fan clutch. They use a separate intake air temp sensor to control the CAC fan clutch (which is rarely engaged except in hot weather). It's also not uncommon for the radiator shutters to close on a bus engine and not open again until Spring. Keep in mind, this is all mounted in the rear of a coach where air-flow is poor.

So it not so much an issue of warm-up time to when you feel heat from the blowers but heat loss and maintaining efficient engine temp while cruising on the highway. This Jeep will be prone to this problem due to the large frontal area and poor aerodynamics. Only speculation but if you can cut the heat loss through using a winter front, it may be possible to achieve 4-5 mpg bump in efficiency.

hatchetman · **Posted:** Sat Feb 17, 2007 12:45 pm

My fuel mileage has gone to crap since this cold snap in east central OH. Just ordered a Lund front cold insert for the CRD :evil:

MoLibertyCRD · **Posted:** Sat Feb 17, 2007 3:28 pm

RFCRD wrote:

Just a few cold weather observations from working around heavy vehicle diesels:

1). It is very common to over-chill charged air in cold weather. In general, colder & denser charged air make it possible to burn more fuel and produce more power. I have seen this on buses where you can get a noticable bump in power (and some black smoke) in cold weather. The fuel consumption will also increase by a good 15-20%, no different than my CRD experience over two winters.

2). At all times, the ECM is trying to achieve optimum water temp (193*F according to DDC research from the mid 90's). Water temp get too high or too low, the ECM adjusts the injector pulse & fuel delivery until it reaches optimum. One of the reasons for the drop in fuel economy is the ECM will feed more fuel to engine in an attempt to maintain optimum temperature. A strong clue that this programming is being used is DC's choice to use a viscious water heater.

3). You don't see many winter fronts today because most big trucks & buses have temperature controlled shutter to block the airflow along with clutched fans. A typical OTR bus will have 190* thermostats, 195* shutter-stats controlling the air shutters and 200*+ stats controlling the radiator fan clutch. They use a separate intake air temp sensor to control the CAC fan clutch (which is rarely engaged except in hot weather). It's also not uncommon for the radiator shutters to close on a bus engine and not open again until Spring. Keep in mind, this is all mounted in the rear of a coach where air-flow is poor.

So it not so much an issue of warm-up time to when you feel heat from the blowers but heat loss and maintaining efficient engine temp while cruising on the highway. This Jeep will be prone to this problem due to the large frontal area and poor aerodynamics. Only speculation but if you can cut the heat loss through using a winter front, it may be possible to achieve 4-5 mpg bump in efficiency.

Nice post.

Enough to make me think about some kind of wind block.

cold weather radiator wind block ideas?

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