Maxus FE dropping drastically

[mtb9153]

Well the topic line says it all, not sure why this is happening?  Changed nothing in my driving, I'm noticing also I can't score a 95% or better brake score.  100% is rare no matter how hard I try.  Other than the fact that our morning and evening temps have drastically dropped, I don't know what to make of this change in Fuel usage.  My AvMPG has dropped from 48.5 to barely above 46.1  I don't want to see my numbers fall below 46.0 but I'm afraid it is just a matter of time.  Also this present tank is going to fall short of 500 miles unless I can put a miracle out somewhere with what's left of the tank.

[Jmonty]

ya, she doesn't seem to like the cold very well.   do you keep yours garaged at night?

[wab]

Is the this tank the first to drop?

Maybe you bought some bad gas?

 

The brake score is not good, maybe Maxus reverted to pre 13B07 OR has failed (been corrupted).

 

 

 

Check your pods someone may have turned them 90* :yahoo:

Edited October 21, 2013 by wab

[asb]

Cold weather will hit your mileage.  However, have the dealership hook it up to see if there are any ISD updates for your car.

[Tdefny]

Maybe your driving patterns are somehow different this month (or maybe the traffic patterns).

 

Also take a look at your MPG from last year and you will probably find that you took a drop in late October. I used to go through this every year in the Prius until the pattern became so familiar that it didn't matter to me anymore.

 

Don't sweat it. You have a great car. Enjoy the ride and other cool things until the mileage comes back up again.

[Adair]

I'm seeing the same thing in Michigan. Our temps have only begun to fall.....worse to come beginning this week. I was spoiled in more ways than good MPGs with the warm weather...............now I have to wear socks! and boots! :gaah: and long pants, and coats :rant2:  :redcard:

[fotomoto]

OP is looking at a 5% drop with cooler weather and as others have pointed out this is normal.  Maybe a change in the thread title is in order?  

[Jmonty]

OP is looking at a 5% drop with cooler weather and as others have pointed out this is normal.  Maybe a change in the thread title is in order?  

 

 

lol ya.  2.4 mpg is not drastic by any means.    it's just 2.06 gals/100 miles vs 2.17 gals/100 miles.  no reason to freak out   :kookie:

 

unless i messed the math up, i'm soooo tired today...

[wab]

I didn't think California had seasons.

 

I thought San Francisco was always a little cool?

[RaPieR]

Has the change already been made by refiners to go to winter blend? 

[CMax-Traveler]

I just looked it up, supposedly CA doesn't switch to the winter blend until Oct 31st, except for last year due to the refinery outages when they switched mid-October...  But the switch to winter blend does usually cause a 5% drop in mpg in all cars.  Anyone have any more recent info from CA?

 

I don't think a 95% versus 97% brake score would make that much of a difference.  I wouldn't imagine you'd start noticing a sizable MPG hit unless you're sub-90% on the brake score.

 

Without knowing more specifics, my guess would be the change is due to the warm-up cycle for the engine.  Is your engine staying on longer?  My MPGs have dropped a little bit too, but I've been able to mostly counteract them by changing my habits a little bit.  I've noticed two things:

1) The engine warm-up time (when the ICE is forced to be on) gets longer as it gets colder outside.  If the outside temp is <60, I've noticed a minute or two longer in the first warm-up cycle.  Since there's a stop light just down the street, I just do my best to get to the light on battery (which meant turning off EV+ so I have a higher battery level in the morning), so my ICE warm-up cycle is while I'm driving rather than sitting at a light.

2) I also noticed that if I have my heater on when I start the car and it's set >10 degrees higher than the outside temperature, the ICE turns on almost right away and doesn't shut off until the engine is fully warmed up.  So I've just started turning off the heat when I first get in the car (and always wearing gloves!), then turning it back on during the second ICE cycle -- the heater doesn't do much anyway for the first few minutes anyway...

Doing those two things has effectively gotten me back to close to my summer MPGs.

 

Adair - I'm with you on the coat and gloves thing, grrrrrrrr... I'm definitely not looking forward to the drop below freezing that's forecast later this week!

Edited October 21, 2013 by CMax-Traveler

[Adair]

Where did you look that up CMax-Traveler? I wonder if it's winter blend here in MI already?

[obob]

Could you expand on this?  Why does this improve efficiency?

 

Thanks.

 

2) I also noticed that if I have my heater on when I start the car and it's set >10 degrees higher than the outside temperature, the ICE turns on almost right away and doesn't shut off until the engine is fully warmed up.  So I've just started turning off the heat when I first get in the car (and always wearing gloves!), then turning it back on during the second ICE cycle -- the heater doesn't do much anyway for the first few minutes anyway...

Doing those two things has effectively gotten me back to close to my summer MPGs.

 

 

Edited October 21, 2013 by obob

[C-MaxSea]

OP is looking at a 5% drop with cooler weather and as others have pointed out this is normal.  Maybe a change in the thread title is in order?  

Ditto

[HPRifleman]

Well the topic line says it all, not sure why this is happening?  Changed nothing in my driving, I'm noticing also I can't score a 95% or better brake score.  100% is rare no matter how hard I try.  Other than the fact that our morning and evening temps have drastically dropped, I don't know what to make of this change in Fuel usage.  My AvMPG has dropped from 48.5 to barely above 46.1  I don't want to see my numbers fall below 46.0 but I'm afraid it is just a matter of time.  Also this present tank is going to fall short of 500 miles unless I can put a miracle out somewhere with what's left of the tank.

 

While you can expect the MPG to do down when the weather is cold, the lower brake score is puzzling.

 

In the past were you able to reach 100% braking on most of your stops? Do you feel like you are braking differently? Have traffic patterns changed to cause you to  have to hit the brakes harder?

 

Our temperatures are dropping here in the midwest and so is my mileage. A trip that used to be 50-55MPG is now 45-50MPG. Still, I can reach a 100% brake score on almost all of my stops just like I have since owning the C-Max. I would not expect the brake score to change with the season. Maybe others who went through last winter with the C-Max can comment?

[drdiesel1]

Time to install the block heater and use a timer to have a warm engine at drive time. 

Set it two hours before you leave the house.

Edited October 21, 2013 by drdiesel1

[CMax-Traveler]

Where did you look that up CMax-Traveler? I wonder if it's winter blend here in MI already?

 

Adair - the CA blend switch date was mentioned in this article that I had seen back from the refinery outages last year.  Not sure about Michigan, but it's entirely possible.

 

 

Could you expand on this?  Why does this improve efficiency?

 

Thanks.

If having the heater on forces the ICE to run, the ICE is running all the time -- even when it would normally be in EV mode (like when you're coasting, or sitting at a stop light / stop sign).  So, having the ICE on, burning fuel to warm the engine, dramatically lowers the MPGs in the early part of a trip.  Especially if you're sitting still or would otherwise be in EV.

 

Typically, after the initial warm-up cycle (which 13B07 shortened), the ICE is allowed to shut off, so the vehicle goes into EV mode as needed, like normal.  But the heater apparently prevents (or delays?) that until the engine is warmed.  Once the engine is warmed up, I don't think it makes much of a difference.

 

Does that make sense?  I'm not sure if that clarified things or made it worse...  I'm also talking anecdotally here, I don't know what the car is actually doing, only what I've observed so far.

[mtb9153]

ya, she doesn't seem to like the cold very well.   do you keep yours garaged at night?

Maxus has never been kept outside I'm happy to say.

[Tdefny]

The heater penalty is even bigger on the Energi because it has electric heat. I usually don't turn the heat on until the ICE is fully warmed up, so the trip can get a little chilly on all EV days or I will end up burning gas for the last mile or two of the trip home. Luckily the heated seats work really well.

 

One unexpected benefit- if you drive that way when it is snowing the snow that lands on the car doesn't melt and form a layer of ice the next morning.

[ptjones]

I just looked it up, supposedly CA doesn't switch to the winter blend until Oct 31st, except for last year due to the refinery outages when they switched mid-October...  But the switch to winter blend does usually cause a 5% drop in mpg in all cars.  Anyone have any more recent info from CA?

 

I don't think a 95% versus 97% brake score would make that much of a difference.  I wouldn't imagine you'd start noticing a sizable MPG hit unless you're sub-90% on the brake score.

 

Without knowing more specifics, my guess would be the change is due to the warm-up cycle for the engine.  Is your engine staying on longer?  My MPGs have dropped a little bit too, but I've been able to mostly counteract them by changing my habits a little bit.  I've noticed two things:

1) The engine warm-up time (when the ICE is forced to be on) gets longer as it gets colder outside.  If the outside temp is <60, I've noticed a minute or two longer in the first warm-up cycle.  Since there's a stop light just down the street, I just do my best to get to the light on battery (which meant turning off EV+ so I have a higher battery level in the morning), so my ICE warm-up cycle is while I'm driving rather than sitting at a light.

2) I also noticed that if I have my heater on when I start the car and it's set >10 degrees higher than the outside temperature, the ICE turns on almost right away and doesn't shut off until the engine is fully warmed up.  So I've just started turning off the heat when I first get in the car (and always wearing gloves!), then turning it back on during the second ICE cycle -- the heater doesn't do much anyway for the first few minutes anyway...

Doing those two things has effectively gotten me back to close to my summer MPGs.

 

Adair - I'm with you on the coat and gloves thing, grrrrrrrr... I'm definitely not looking forward to the drop below freezing that's forecast later this week!

I was wondering if you have ScanGauge so you would know the exact temp you were at? Ford said 202-212degrees is normal operating temperature. My guess is your temps are lower than that. We are coming into Grill Cover seasons. BTW I left mine on all year.

Paul

[fotomoto]

I was wondering if you have ScanGauge so you would know the exact temp you were at? Ford said 202-212degrees is normal operating temperature. My guess is your temps are lower than that. We are coming into Grill Cover seasons. BTW I left mine on all year.

Paul

 

I didn't get my SGII till Sept. so I missed peak summer temps but the highest I've seen so far is 202f with afternoon temps in the mid-90's.  IIRC, the 202F reading was in the mid-80's during some city traffic.  FWIW

[ptjones]

I didn't get my SGII till Sept. so I missed peak summer temps but the highest I've seen so far is 202f with afternoon temps in the mid-90's.  IIRC, the 202F reading was in the mid-80's during some city traffic.  FWIW

Usually your highest temps occur when going uphill at hwy speeds with AC off. The more the ICE runs % of the time the hotter it gets. In theory the leaner the ICE runs, the more efficient it is. There is a MAX temp. limit which should equate to the coolant temp. Someday maybe we can figure out what that temp. is. IMO I think Fords latest update increased FE by leaning the ICE. 

Paul