My 2000 Ranger 4X4
I have a 2000 ranger 4x4 3.0 V6 and for awhile I was only getting 10-13 MPG in the city and asked ford what the problem might be because I told them that when my gas cap is on that I can still push down on it about 1 inch. They wanted me to bring it in and they wanted to do some testing which would set me back $100. I refused and said that I'll try something before and see if thats the problem. I bought a new stant locking gas cap at advance auto parts and put it on and immediately noticed that it DID NOT budge like the original one did. It turns out that I was slowly leaking gas fumes out of the cap but not enough to trigger the service light. I ran a full tank when I changed caps and it went up to 17-20 MPG(highway) 15-16(city)and I also noticed a slight horsepower jump as well. To those who read this and being ranger owners, CHECK YOUR GAS CAPS AND SEE IF THEY ARE LEAKING. Later
Matt K
Story replies
Way to go Matt. I knew this was you right away. I suggested you were loosing fuel through that loose cap. Glad you are getting better gas mileage. See you at work.
I have a 99 ranger 4X4, 3.0 and found that if you run mid grade fuel I get 4 extra miles a gallon. My ranger gets 28 mpg with mid grade - highway, but burning high grade does not add anything.
Vapor loss at a rat of equaling 3 to 4 MPG? I don't think so. If you can get a scanner and drive it around monotoring the coolant temperature I'll bet that it isn't reaching 192 to 195 degrees and under 15psi cap pressure. Your thermostat is partially stuck open and the cap isn't maintaining 15psi. coolant pressure, keeping the coolant temps low. The PCM will run the engine rich as if a carb. choke was closed, running the engine rich. A thermostat and a 15 pound cap will retore the MPG. to the original numbers.
Running high octane fueles in a low compression engine without high loads will carbon op the combustion chambers causing detonation. Using high octane fueles in low compression engines means that the anti-knock additives will not be used as intended and remain in the combustion chambers eventually building up and even causing engine knock from contact between the head-carbon-piston. If the engine doesn't require high octane fuels using them can damage the engine.
I though our Explorer was getting unheard of mileage until we got a Tom-Tom and got a very different speed reading. Larger tires and the wrong gear at the transfer case made for some impressive mileage. Not. A 4.0L engine gets in the 17MPG range. Nowhere near mid-20's. Even in the mountains in high elevation it's just a couple mpg, not 10mpg.
2000 ranger 4.0l manual transmision 50 miles on high way at 67 mph but 15mpg in city driving