[Johnodie]

Change my mind. J/K
regular mode =22.3 mpg
sport mode = 24-25 mpg

Been having an issue with my Foz over the past 2 or so years with bad MPG, and not starting in severe cold(for my area -5F) or drastic change in temperature overnight, as well as weird/hard/quick up then down shifting, as well as occasional rough-ish idleing (could just be regular H4 engine shakey-ness). All that said I've been paying attention to MPG. I did the idle relearn after the battery was replaced, thinking it was keeping the car from starting.Put new AGM battery in and thought I would be good, only to need my battery pack jumper the following week last winter to start it. Woe is me. changed plugs, changed wires, changed out ignition coil pack. Still randomly get poopty gas mileage. One week im at 25 combined and the next 22 with no real change in driving habits or travel length.

I had put the car in Sport mode and drove awhile and got real good MPG reported on the clock display. Stop, shop, get back in and only use Non-sport mode...instantly MPG goes down. Tested today at lunch with buddy in car, and sure enough i was getting 24.3mpg otw to work and to lunch, put it in reg mode and it drops in less then 1000ft to 24mpg, throw it in Sport mode and MPG goes back up.

Dont get me wrong I like sport mode in that the gear holds longer making for more controlled accelerationand deacceleration when changeing lanes and whas nots, but am i really getting better gas mileage. The previous owner mentioned something about his mechanic trouble shooting a bad MPG issue before he sold it to me and said the last thing the mechanic though it was to check/replace was the throttle pedal.

Now i will drive to Annapolis from the DC beltway (25 mile) this evening and then to Home in Glen Burnie (another 15-20miles) later and will leave it in Sport mode to test but I'm pretty dang sure for whatever reason my car is functioning better in Sport mode than it is in regular mode. Can someone explain why!!!!!!!!????????!!!!!!! Is it my acceleration pedal as previous owner mechanic suspected

in synopsis:
NO CHECK ENGINE LIGHTS
battery changed
plugs changed
wires changed
MAF cleaned
transmission fluid drained and filled 4 times (4 quarts each time at 300mile interval) total of 16 fresh quarts mixed in there. (NO its not overfiled i've checked)
oil changed
ground points cleaned brushed and greased with new ground straps
boinked your mother for good luck


Anyone experienceing somthing similar??

 

[HeyChris]

I routinely get crappy gas mileage in normal mode. But I'm 90% city the last few months.

Sport provides better mileage if I stay off boost. Maybe placebo, but it seems that way.

 

[Johnodie]

I routinely get crappy gas mileage in normal mode. But I'm 90% city the last few months.

Sport provides better mileage if I stay off boost. Maybe placebo, but it seems that way.

I aint got no booster. I'm waiting till I have to fill up the tank to see if the above radio guage is accurate for MPG, when compared to actuall miles/gallons of gas into tank. We shall see. I drive mostly Highway M-F but its on 95 and 295 which are notorious for backups.

 

[Johnodie]

Update:
Head gasket leaking oil around #1 cylinder. Had gasket replaced, along with timing chain and pully, spark plugs, water pump, thermostat, AC and alt belt, and battery(died at shop for no apparent reason). Then replaced sprak plug wires, an wrapped ends with high voltage electricle tape to prevent arcing from boot/wire to engine/iginition pack. This morning in Maryland it was 21F, car would not start, just turn over and over. Jump Pack didnt help, just prolonged my ability to try and start it.stopped after 5 minutes of flipping key to on to prim the fuel pump and warm up the MAF temp sensor. Gave up and went inside to make coffee. Came back out 10 minutes later; key to on, waited ten seconds, turned off radio, turned key with turn over, no start after 4 seconds, key off, key to on, wait 5 seconds, turn key, turn over stutter....stutte....Combustion!!! Smelled a little fuel, but cant imagine I flooded it earlier, idk. Gas mileage is still low, and im not happy.