Quick question....

[SeanM]

This question I am asking for my girlfriend who has had her 1995 Ford Explorer XLT 4x4 Control Trac(bone stock for now) for about 4 months. She bought it used and it has about 60k miles on it now. She wanted me to ask this question, which I believe I already know the answer to. Here's the question:

"If the truck tends to run cool, could that cause bad gas mileage?"

By "cool" she means running in the lower end of the temperature range, within that little arc, hovering slightly above the "C". I told her that actually it is better for gas mileage because it means that a denser charge of air is getting to her engine which also means a slightly higher amount of power. Thus, because of the slight increase in power, the need for mashing the gas pedal is decreased(she doesn't drive all that fast). The truck, however, does not get good gas mileage (somewhere between 10-16 mpg). It is only a V-6 OHV. Anyways, please answer the question if ya could...Any input would be nice...Thanks guys...

Sean
___________________
'95 XLT 4dr 4.0L V6 OHV Auto
Flowmaster 40 series Cat-back
K&N FIPK
Bosch 4+ Platinum plugs
Splitfire ignition wires
PIAA 9007 Super-White Headlights(adds 40 rearwheel hp )
Superchip (Installed soon!!)

 

[Ru Dawg]

Sean, I have the same year 'splorer. I'm seeing almost the same temp..mine's not as low...but low. I definetly noticed a drop in mileage when the cold weather hit. Your theory would be true in a carburated engine...i.e..no computer/efi system. The colder coolant temp actually cause the computer to make the engine run "rich" IOW's...burning up extra gas.

FIX: First try resetting the puter (disconnect battery for 5-10 minutes then reconnect). This may help because the computer will "relearn" the cold air temps. Also may wanna replace the thermostat..make sure it's a 195*F one.

Hope this helps man!

 

[mtuck]

Sean, it sounds like the t-stat is either stuck open, or it is missing (which was the case when I bought my used '91). A warmer engine (with the temp needle between the O and R of NORMAL) will produce better gas mileage. Your therory of colder is better is correct when dealing with the temperature of air coming in to the intake manifold. Colder air = denser air = more oxygen for combustion.

When I put a 195 degree t-stat in my Explorer, I picked up about 2mpg. Also the heater will feel much warmer.

Just my 2 cents. Hope this helps.

mtuck

 

[LazyDay]

With these computer controlled engines you have to make sure that the engine is running at design temperature - 195*F. If the engine is cooler the computer thinks it needs to dump more gas into it to heat the thing up and thus runs rich and wastes gas. Definetely replace the t-stat with a 195*F. You should be running about 40% up the scale on your gauge. At least that's where I'm running on my '95 after replacing mine a couple of weeks ago and yes it did help by about 2mpg.

 

[SeanM]

Ok...well, should I replace it with a so-called "performance thermostat" such as those offered from JET? Also, will I really see a mpg increase?

Sean
______________________
'95 XLT 4dr 4.0L V6 OHV Auto
Flowmaster 40 series Cat-back
K&N FIPK
Bosch 4+ Platinum plugs
Splitfire ignition wires
PIAA 9007 Super-White Headlights(adds 40 rearwheel hp )
Superchip (Installed soon!!)

 

[PunkChild]

I don't think you'll get any performance out of a thermostat, but it deffinatly sounds like a stuck thermostat. I had it happen to my truck a week ago, the needle never went much higher the the C.

 

[whyisshane]

I have a 94 explorer with an a4ld, reverse no longer works and I am wondering about putting a maual in it. what models/ years can i choose from for donors?