Engine Block Heater on a gas KJ?

auggy · **Posted:** Sun Jan 08, 2006 3:03 pm

What are the advantages of installing an engine block heater on a gas KJ? Since winter started my gas milage has tanked to around 11 mpg (and I have since taken to driving like a grandma in an attempt to counter the problem to no avail). Would an engine block heater help? Is the extreme drop normal? (I used to get around 16 mpg) What else could I do?

Oh, the KJ has about 4800 miles on it and is not yet a year old.

Thanks for any help.

auggy · **Posted:** Sun Jan 08, 2006 11:33 pm

Anything that could help? I'm open to any suggestions .. or is this just normal?

wolfheartak · **Posted:** Mon Jan 09, 2006 3:36 am

If your outside air temp drops below 20F, a block heater is helpful - and that's the norm up here to plug it in, although I don't ususally bother unless it's going to be below zero. But sometimes I still have to crank it for a while to get the car to turn over ( <-- edit: If I don't use the heater when it gets close to zero). It decreases wear and tear on your engine, improves winter gas mileage (winter gas mixtures play a part too if your area gas stations do that), as well as reduces emissions from a cold start.

I don't know how much the cold really affects gas mileage, but I do notice a difference w/ my vehicles (Honda and XJ both)

Found this link from Montana that's got some good info for you:
http://www.co.missoula.mt.us/envhealth/AirQ/AdvisoryCouncil/Projects/EngineBlockHeaters.htm

-Marisha

Taz · **Posted:** Mon Jan 09, 2006 7:54 am

There a number of things that affect winter mileage. Most states add Ethanol in the winter to help combustion and reduce the unburned hydrocarbons from tailpipe exhaust. Whan an engine is cold the computer will richen the fuel air mixture. Until the tranny fluid warms up a lot of newer automatics don't go into overdrive or lock up the torque converter. A block heater will help the engine warm up a little faster and the mixture will lean out faster, also as a driver you may not let it idle as long before you take off which will make an impact. I have a heater on the CRD and use it. But I also use the one on my wife's Rendesvous.

OBX KJ · **Posted:** Mon Jan 09, 2006 1:46 pm

I have block heaters on both my KJ and TJ. They are a great help. I have noticed that the TJ's is much more effecient than the KJ's, both OE Chrysler parts. Could be due to the placement. The TJ's hood will just get wet when the rest of it is covered in snow and ice (keep in mind no hood insulator pad). The easy start ups and ultra fast heat are nice additional benifits.

Jeepjeepster · **Posted:** Mon Jan 09, 2006 3:31 pm

I would say its b/c the kj has the insulator pad under the hood.

OBX KJ · **Posted:** Mon Jan 09, 2006 5:04 pm

Pad or no pad, the TJ develops heat much faster. Was a little dissapointed w/the KJ's block heater. Still much better than not having it at all !!!

auggy · **Posted:** Mon Jan 09, 2006 7:51 pm

Thanks for the help .. anything else that could help improve miliage other than a block heater? I'm sure that gas stations around here use winter mixtures as Northeast Ohio is COLD

wolfheartak · **Posted:** Tue Jan 10, 2006 12:41 am

Don't know if it will help your mileage, but don't let the tank get under 1/2 if it's going to go below or close to freezing, especially if you're not driving it everyday. Condensation can build up inthe tank and that's not good for anything on you're jeep.

And in the winter the air pressure in your tires will vary faster. So check them more often All the thing you would normally do for mileage (tires, spark plugs, oil changes, etc) don't forget about.

If I think of anymore little tibits I'll let you know.

-Marisha

ManicMechanicJoe · **Posted:** Tue Jan 10, 2006 10:24 am

Your KJ probably has a block heater-I have yet to see one without-check under the airbox. It won't help fuel mileage (much) but it will make your starter last a lot longer and you engine warms up faster. Optimum fuel mileage is achieved when the vehicle is at its normal operating temp, so you will save a little gas but you won't notice a difference.

Do not let the vehicle idle to warm up. This is a huge waste of fuel, if the vehicle is not moving you are getting 0 mpg. Warm up the vehicle by slowly driving it for the first 5 minutes, keep the RPM's down as low as possible. I used to let my Jeep idle untill I saw that tip on the EPA's website-I save $20 a month by warming it up with easy driving (say going from your house to whatever highway).

If it's 20 degrees, and the Jeep will be sitting for more then 2 hours-plug it in where possible. It will make a huge difference. Plug it in right after you shut the vehicle off (most people plug it in before going to bed, this is wrong). The idea is to keep the vehicle warm with a block heater, not warm it up.

If it's really cold, like 0 or colder-thank god you don't have an old diesel, my last pickup was a 20 year Chevy-It got so cold and so hard to start-I let it run and idle for a month straight (diesel was $1.50 a gallon and they can idle better then gassers folks, a starter costs $280 for that truck and only used an extra $20 in fuel that month.

Bearcatrp · **Posted:** Fri Jan 27, 2006 12:39 am

Put 100% synthetic in it for the winter. If you can afford it, use it year round. With synthetic, you won't need a block heater. Turns over the same above and below zero. You will see improvement.

snowsport · **Joined:** Tue Oct 18, 2005 11:52 pm **Posts:** 1211

Absolutely right. After driving 30+ years in an extremely cold climate, I have learned that: a) get synthetic oil. b) plug the car in. Very simple rules to live by in the cold.

padrino · **Posted:** Fri Jan 27, 2006 12:44 pm

Block heater?? What's that???? Haven't seen one of those in our parts. :lol:

Padrino

ManicMechanicJoe · **Posted:** Fri Jan 27, 2006 1:34 pm

if you live in san diego-I wouldn't worry about it. Really only helps below zero

KJ33 · **Posted:** Fri Jan 27, 2006 8:47 pm

The block heater is really just to help your Jeep start when it otherwise wouldn't. With modern EFI and elec. ignition motors, it's really not necessary to plug it in, unless it's below 0 (-20 C). Yes, your Jeep will warm up faster after it's been plugged in, thus getting a little better mileage for the first 5 minutes (ONLY), but the effect will be negligible, and the cost of the electricity to plug it in will be far greater than the value of the gas saved. If you're having trouble starting in the cold - plug it in. If not, don't bother - just drive slowly the first 5 minutes, like the man said above.

Julius8122 · **Joined:** Mon Jan 09, 2017 4:51 pm **Posts:** 1

I've looked and looked for mine, but I can't find it. Could really use it, since it's been 0 and under for days.

Engine Block Heater on a gas KJ?

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