whats up guys. i have a 2002 egde, i just recently did a tune up on my truck with about 35,000 miles on it. I changed the spark plugs using Autolite double platinums. Changed the thermostat with a stant 180. I flushed the coolant and changed the fuel filter. After i did that my mileage per gas tank went way down. I was already gettin horrible mileage having a 3.slow with 32's and stock gears. On my gas guage every quarter of a tank i used to get a little over 50 miles. But now i get like 35 to the quarter. the total tank i lost atleast 25 miles. What do you think could be casuing this. I thought maybe a plug went bad or something. but i have no check engine light and my truck runs fine. Help Please........

 

i believe a 195 t stat is recommended.

 

I tried a 180 t stat for a while in my 93 4.0, and my mileage went down, replaced with a 198 t stat and it's back to normal.

 

i dont see how a thermostat can take like 30 miles off my tank.....

 

believe It.
Dave

 

how dose that effect the mileage?

 

The engine is designed to operate at a certian temp when fully warm, in this case about 195 degrees. At lower temps and when the engine is in open loop operation, it's going to run richer. Rich = poor mileage. Your situation is such that the computer thinks it's not fully warmed up and is making it run rich. Replace the thermostat with the correct temperature thermostat. Also, checking mileage by looking at 1/4 increments on the gas gauge is not an accurate way to evaluate mileage. You really need to run maybe three full tanks through it and factor in the total miles and the gallons consumed. 1/4 tank on the gauge does not equal 1/4 of the fuel tank capacity.

 

I put a 180* thermostat in my 3.0 Ranger about 6 months ago. My motor ran fine after that. At the same time I installed a DZK underdrive pulley on the crankshaft. My gas mileage after that went from 18 mpg to 20 mpg. From what I've read on the net, I think the Autolite double plats. are pre-gapped from the factory to something weird. The folks who regap their plugs seem to have a decrease in gas mileage. Again this is what I've gathered from reading many posts, so take it with a grain of salt!

 

yeah i think i read somewhere about the autolites. I you regap them from what they already are then your mileage takes a crap. if my truck was running rich then it would feel like it dose in the morning when i start it up. When i first take off it has some kick to it because its running rich. After it warms up it goes away, so my truck is not running rich throughout the day all warmed up.

 

I was just wondering why you put a 180 deg thermostat in the truck and why the plugs at 35K when the tuneup call for 100k on plugs.
Dave

 

general maintanence. an i dont know of any plugs that actually last 100k. if you look in the service manual the truck comes with they recomend changing plugs at 35k

 

I am wondering if the same would be true for the 4cyls in our lives. As my truck never gets above 190 per my temp guage.