Fuel Mileage - Do the Math

[jmckinley]

Like everyone else, I'm irritated that I'm nowhere near 47 mpg no matter what I do.  Yes, my car is less than 2,000 miles and it's winter and Your Mileage May Vary etc, etc.  But I'm reasonably sure I'll never ever see 47 mpg combined mileage without resorting to extreme dorky driving.

 

But, when I do the math, I find that it isn't all that bad.  If I drive this thing until the Hybrid warranty runs out (80,000 miles) and gas hangs around $3.50, it works out like this:

 

Cost to drive 80,000 miles at 40 mpg = $7,000

Cost to drive 80,000 miles at 47 mpg = $5,957

                                         Difference = $1,043

 

So if it takes me 5 years to do the 80,000, that's $200 per year.  Maybe I should just drive the damn thing and quit worrying about mpg.

[C-MaxJaxon]

I love using the calculator on the EPA site. The small annual cost difference is surprising to many people. It's about the percentage of difference, not the number of miles difference.

 

http://www.fueleconomy.gov/feg/savemoney.shtml

[ptjones]

Like everyone else, I'm irritated that I'm nowhere near 47 mpg no matter what I do.  Yes, my car is less than 2,000 miles and it's winter and Your Mileage May Vary etc, etc.  But I'm reasonably sure I'll never ever see 47 mpg combined mileage without resorting to extreme dorky driving.

 

But, when I do the math, I find that it isn't all that bad.  If I drive this thing until the Hybrid warranty runs out (80,000 miles) and gas hangs around $3.50, it works out like this:

 

Cost to drive 80,000 miles at 40 mpg = $7,000

Cost to drive 80,000 miles at 47 mpg = $5,957

                                         Difference = $1,043

 

So if it takes me 5 years to do the 80,000, that's $200 per year.  Maybe I should just drive the damn thing and quit worrying about mpg.

Did you read 3mpg gain with grill cover threads?

[PWBarrett]

If the grill covers are about warmth not aerodynamics, then I figure (at least where I live), they'll provide no benefit half of the year.

So an average of 1.5 MPG would save me about $30 per year.

[ptjones]

If the grill covers are about warmth not aerodynamics, then I figure (at least where I live), they'll provide no benefit half of the year.

So an average of 1.5 MPG would save me about $30 per year.

At 70mph it's 3mpg aero, 1mpg heat.  So at 55mph it's 2mpg aero and 2mpg heat. And 40mph it's 1mpg aero and 3mpg heat. Below 62mph you are running in EV mode and ICE isn't creating heat all the time so covers reduce heat lose. Which saves MPG's.

[CNCGeek]

So if it takes me 5 years to do the 80,000, that's $200 per year.  Maybe I should just drive the damn thing and quit worrying about mpg.

I agree, you probably won't get 47mpg, maybe 42, without resorting to hypermiling or mods, or maybe 38-40 if you just drive it reasonably.  I try to drive for economy, but am not going to be the guy holding up traffic to do it, fortunately I drive often when other people don't.  The C-max is a nice car and you should just enjoy it, the economy is still good (I'd of bought it if the more likely 42mpg was the EPA number).

[jmckinley]

I might have sprung for the CMax at 42mpg.  My decision was based on the mileage, the hatchback/flat floor, higher driving position and the ability to tow it four wheels down.

 

Like all hybrids, even at 47mpg the financial equation doesn't justify the extra cost unless you keep it for 10 years. In fact, the best financial solution would have been to keep my 8 year old Chrysler minivan which is paid for and gets 27mpg at 75mph and 20mpg in town 

 

Other contenders were the Focus -  interior colors sucked, some problems reported towing the six speed auto

                                           Escape- too big, pricier, also reported problems towing

                                           Volt------Uncertain reliability, uncertain approval to tow, uncertain IRS credit

 

You're right, it is a nice car and I enjoy driving it if I can keep my eyes off "Engage" etc.

[PWBarrett]

I wonder how it would have been if this car had first come out in say, April, instead of right at the onset of cold weather.

[ptjones]

I wonder how it would have been if this car had first come out in say, April, instead of right at the onset of cold weather.

On my graph for uncovered grill 27degree temp change = -5mpg. For covered grill 27degree change =-7mpg they should be pretty close.

[kechair]

I agree, you probably won't get 47mpg, maybe 42, without resorting to hypermiling or mods, or maybe 38-40 if you just drive it reasonably.  I try to drive for economy, but am not going to be the guy holding up traffic to do it, fortunately I drive often when other people don't.  The C-max is a nice car and you should just enjoy it, the economy is still good (I'd of bought it if the more likely 42mpg was the EPA number).

Well said, guys. Well said. I am in your camp - not going to be a safety problem on the road by driving too slow or an irritant, I drive fast when I need to, and am happy about close to 40 (39 mpg in my case). I can't take my eyes off the Enpower screen though. Actually I enjoy the 'Eco video game'. It's sort of like I enjoy any other challenge so there is a bit of competitiveness in me like I think most if not all of us have who read this forum, to maximize mpgs which is why there is a lingering 'darn I wish I can achieve 47 mpg' in me. I also expected far less than 47 (40) so I don't have any problems with the FE. There are of course some who will be upset purely based on the principle of the thing (the thing being that 47 is advertised, not close to actual for some). I respect that too. To each his own.

[joe]

When we became interested in the C-Max, the epa numbers were not out yet.  We bought the car because of factors other than mpg (cargo space, seating, features).  It is going to replace an old mini van which gets 15 mpg city and 22 mpg highway.  In reading through the different comments, I've learned to alter my driving habits which should help get good mpg.

*  Accelerate moderately, get up to speed (35 mph limit or higher) and then back off a little to get into EV mode.

*  Accelerate slower if speed limit is under 35 mph - I'm able to stay in ev mode.

*  Our C-max is garaged so even though its 35 degrees (F) outside, the car is around 55 degrees.  So, I turn off the heat system and turn on the heated seats.  This allows me to drive in ev mode right from the start.  After about 5 minutes, and when the car needs to use the engine, I turn on the heater (engine is warmed up by now).  Now I'm getting warm air without sacraficing ev mode at the beginning. 

*  With only 250 miles so far, my Trip 1 is slowly growing - currently 35 mpg.  But some short trips have indicated as high as 52 mpg, while some really short trips (less than 2 miles) have been as low as 25s mpg.

 

Of course, temps, terrain, and driving habits all influence mpg.  But when you do the math, the difference between 35/40/45 mpg isn't that much.