Hot engine on highway?
 

I noticed recently that

a) my mileage has gone down
b) a lot of heat comes through the vents when cruising on the highways, 6th gear, ~4k rpms. This is with the fan setting turned down to zero (off).

I'm wondering if these two issues signal something's not working right, or whether this is normal. I don't remember the vents being so warm the last winter though. I'm not sure if cold weather has anything to do with the mileage as well, it's been cold up here in eastern Canada lately. I was definitely getting better mileage last winter, but that was with a different flash as well (pre 4206F).

I have the same issue on the highway. also my first gear hesitates and jiggles before engaging. only in first gear. but that heat on the highway mixed with the low mpg is makeing me think somthing up.

also the dealer has no clue

they refer every problem to the coils

Yeah I'll probably talk to my dealer about it on the next oil change. I wonder if they will refer to the coils as you say, hahaha

The only thing the recall changed was the OMP rate.

Sorry to ask but what is OMP and what does it do?

Not sure what recall your talking about? I know when they did something to the PCM during the engine recall my fans like never come on anymore even after driving for long periods of time. It's odd.

Oil Metering Pump. It injects oil into the rotor housing to lube the rotor seals. Mazda found that the amount of oil being injected was insufficient, so they increased it in the latest flash.

I'm not sure if that is the ONLY change made in the new flash. Many others have reported a drop in gas mileage after the recall, so I suspect they also made some changes to the fuel maps. Others have speculated that the car may also go into "open loop" in some situations where the car would have stayed in closed loop with previous flashes, like sustained high speed driving. This could also cause some issues. For me personally, the flash doesn't seem to have had any effect on mileage.

As for the heat at high speed, I think this is normal. If your temperature dial is all the way in the red, all of the air entering through the HVAC will be heated by the coolant. If your fan is off, you will still get air coming in because it is being pushed in to the car as it moves (the faster you go, the more air gets pushed in.) In other words, having the fan on "0" doesn't stop airflow, it just doesn't actively push it along either.

Yes Marc_GS, I think you are right with the heat coming through the vents no matter what. I turned the temp dial down to blue this morning coming to work as a test and yeah, less hot air passing through for sure. I don't remember this last year, or maybe I just enjoyed the "free" heat, haha :p