Idling or short EV trip MPG

[seansrq11]

I have a new C-Max and am in love with this car. Have been very disciplined and have been getting the promised MPG numbers or even higher. My one concern is with the low MPG scores I get after idling (yesterday, sat for 20 minutes with sleeping baby with AC running MPG score was 25). Idling means no load on engine and should have a higher score just like when coasting when MPG gauge goes up to 60+.

 

Also, drove across a parking lot the other day in EV mode only and MPG score was 19. (No gas used at all)

 

Now, when I drive longer distances, 20 miles mixing city/highway, I have gotten scores between 45 and 55 mpg on these trips so I couldn't be happier.

 

I am just worried that the low scores are hurting my Lifetime Summary when they should be higher and helping.

 

Anyone have any experience with this and have an explanation as to why the on-board computer would tell you you got 19 mpg's but used 0.0 gallons? Same deal with the no load idling?

 

Thanks in advance!

[HPRifleman]

Can you clarify what gauge you were using that displayed these numbers?

 

The C-Max has multiple mileage counters that can be reset. For example, if the large digital gauge in the center of the left display has not been reset it may read lower because it is using some previous low-MPG values. This will be different than the "last trip" MPG that you see when you shut off the car.

[seansrq11]

Can you clarify what gauge you were using that displayed these numbers?

 

The C-Max has multiple mileage counters that can be reset. For example, if the large digital gauge in the center of the left display has not been reset it may read lower because it is using some previous low-MPG values. This will be different than the "last trip" MPG that you see when you shut off the car.

 

It is the last trip reading after turning off car. The first one that refers to what you just drove. I can try resetting everything and starting over, when we bought the car it had 400 miles on it and the Lifetime was at 13, we are now up to 39 Lifetime and climbing.

[fotomoto]

 Idling means no load on engine and should have a higher score just like when coasting when MPG gauge goes up to 60+.

 

 

 

Incorrect.   The hybrid battery doesn't hold enough charge (power) to run the a/c for long lengths of time.   Periodically, the gas engine (ICE) will run to turn the electrical motor/generator that recharges the hybrid battery.   When the ICE is running in an idling car, it is getting 0 mpg.   That's why traditional vehicles' mpg suck in stop and go traffic.  A pure EV trip will register 999 mpg so anytime you see less than that the ICE has run.   Your 25 mpg rating may sound crazy low but that is twenty five times better than 0 mpg.   :yahoo:

 

For a while, I suggest you select the ICE tachometer option in "My View" to better tell when the ICE is running.  Under light loads, the ICE in the CMAX is very hard to hear or feel which is a good thing and the more break-in miles the smoother it gets.   :rockon:  

[seansrq11]

Incorrect.   The hybrid battery doesn't hold enough charge (power) to run the a/c for long lengths of time.   Periodically, the gas engine (ICE) will run to turn the electrical motor/generator that recharges the hybrid battery.   When the ICE is running in an idling car, it is getting 0 mpg.   That's why traditional vehicles' mpg suck in stop and go traffic.  A pure EV trip will register 999 mpg so anytime you see less than that the ICE has run.   Your 25 mpg rating may sound crazy low but that is twenty five times better than 0 mpg.   :yahoo:

 

For a while, I suggest you select the ICE tachometer option in "My View" to better tell when the ICE is running.  Under light loads, the ICE in the CMAX is very hard to hear or feel which is a good thing and the more break-in miles the smoother it gets.   :rockon:  

That's true, I spoke to soon saying "no load" and yes the engine was running but why would I get better mileage starting and stopping (with a/c running) which uses way more energy than just sitting (with a/c running).

 

As far as the parking lot excursion, the computer said 0.0 gallons used but 19 mpg. I will look for that Tachometer option, I did not know it was there and was thinking how nice that would be to have. So thanks for the tip.

 

Ultimately, my concern is the accuracy of the computer and what it says I am getting and what I am really getting. Does your computer jive with your Fuelly calculations? Just started Fuelly so I don't have any numbers yet.

 

BTW, how do you get that Fuelly signature in your posts?

 

Thanks

[zhackwyatt]

That's true, I spoke to soon saying "no load" and yes the engine was running but why would I get better mileage starting and stopping (with a/c running) which uses way more energy than just sitting (with a/c running).

 

As far as the parking lot excursion, the computer said 0.0 gallons used but 19 mpg. I will look for that Tachometer option, I did not know it was there and was thinking how nice that would be to have. So thanks for the tip.

 

Ultimately, my concern is the accuracy of the computer and what it says I am getting and what I am really getting. Does your computer jive with your Fuelly calculations? Just started Fuelly so I don't have any numbers yet.

 

BTW, how do you get that Fuelly signature in your posts?

 

Thanks

Because when you are sitting with the engine on you get 0 mpg: (0 miles / 1 Gallon).  When are you moving with the engine on you get an actual value.

 

For Fuelly, take a look at this: http://fordcmaxhybridforum.com/topic/1560-how-does-fuelly-show-up-on-everyones-posts/

[salsaguy]

Sean welcome to the cmax club. we hope you are enjoying your car. lots of great tips and tricks and experts getting 50-60 mpg and over 600-750 miles on one tank of gas.

 

1. I would suggest to reset your lifetime average so you start it clean to wipe out whatever the dealer and test drivers did to for mpg.
2. Also there is a view on the dash to show what the load is and how much each is affecting your mpg.
3. Also if you have MFT 3.5.1 there is a display in the 8" center display where you can see how the engine and battery and loads paths are being used.

Edited June 22, 2013 by salsaguy

[Jus-A-CMax]

Welcome to the Forum and also congratulations on your new C-Max.

 

Yeah, the Trip Summary only shows 1 decimal place so, eventhough you see 0.0, you might have used 0.08 and it just truncates. Try using the Trip1 or Trip2 which has 2 decimal points. I know, its freaky to see you went like X mile on zero gas used, lol.

[salsaguy]

Sean, what view/ screen are you using on your left screen? Empower, Engage Etc etc?

[seansrq11]

I am using the Patrick Stewart, "Engage!"

 

Happened today, drove 1/2 a mile under 25 mph, got 17 mpg.

 

Will reset the Lifetime and start over.

[fotomoto]

Happened today, drove 1/2 a mile under 25 mph, got 17 mpg.

 

Normal.  Short trips kill mpg and if it's with a cold engine (ICE) it's even worse.  

[seansrq11]

Did some experimenting yesterday. Did small parking lot trips, 1st: All EV no A/C got 999.9 mpg. 2nd: All EV but with A/C 68.8 mpg. 3rd: A/C running and allowed the ICE to kick in 25 mpg.

 

Looks like short trips and A/C are a no no for this computer. Will look forward to see what I get overall when I get an average with Fuelly. 

 

Thanks everyone for your advice.