Me and my wife have a 1985 blazer , and i get conflicting info on which (D) to drive in...One person tells me to use the (D) with the ovel arround it,and the other tells me to use the Plain D....If i am not towing anything,,which one should i use on back roads , and which one on highways???


P R N (D) D 2 1

 

Overdrive or (D) kicks the RPM's down while cruzing down the highway. Resulting in better fuel mileage.

Drive or D is the high gear.

So if you are just driving around, not towing, use overdrive.

 

You should you do D with the oval around it. This is overdrive. D is 3rd gear and (D) is basically 4th gear. in (D) the motor will turn less rpms so you'll burn less gas.

 

I would guess the (D) is the overdrive. Leave it in there. Unless your going up a steep grade, or towing something heavy, drop it to to the drive "D." Leaving it in (D,) will maximize fuel economy on the highways.

"We drive in parkways and park in driveways"

 

I concur.

About the only time that you should have it out of OD (Over Drive or 4th gear) is when you are in some pretty hilly areas towing something. If you are going to be towing, you should really have an auxilliary transmission oil cooler to remove the heat builtup during the hills. Heat is the enemy of all automatic transmissions and will kill them quick. The reason why your friend is telling you to tow in D (drive or 3rd gear) is because the gear ratio (1:1 in this case) will be much more favorable than when in OD making for less stress on the transmission and less heat build up. With a good transmission cooler, you shouldn't have to worry about what gear you put it in even when towing.

 

summit has some cool<------- ha, tranny coolers. The HD cooolers with electric fans on them.

 

The only way I would put a cooler on with its own fan is if I couldn't install it in front of the radiator and had to do a remote install somewhere along the chassis. Save the money or buy a larger cooler. I am very partial to the stacked plate coolers for their robust design. B&M has a nice cooler available from SummitRacing.com.

 

Thanks all,that helps alot...Plan on alot of other questions from me sometime....My wife has a relative who will put on the valve cover gaskets for us,and if we bring the parts,he will only charge $30.00 ..I think i will jump at that offer.... Roy & Mary

 

Not a bad labor charge at all. Hint that you would like them both done.