Mirage CVT or 5-speed: which should you get for best gas mileage/fuel economy?

[MetroMPG]

>>> Short answer? It depends...

Despite the CVT's better rating, it's not necessarily the most efficient.

Long answer? Read on...

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Until we can convince Mitsu that they need to offer us a MUCH taller, "ECO 5th gear" option in the manual transmission (thereby guaranteeing the car's cult status among economy car enthusiasts)...

There is the question of which transmission will deliver the best real-world results when fuel economy is the driver's goal.

We know the 1.2L with CVT is rated better in both city and highway driving than the 5-speed manual. The US EPA (currently the most realistic rating system) says:

Mirage 1.2L fuel economy	City / Highway / Combined
CVT:	37 / 44 / 40 mpg (US)
5-speed manual:	34 / 42 / 37 mpg (US)

Which one you should choose is not a given, despite the higher ratings of the CVT. The manual can outperform it in the hands of a skilled, motivated driver in the right environment.

So, to decide, find yourself in this list of scenarios ...

>>> If you're a "typical" driver (turn key, turn on tunes, go go go)

The CVT is the one to get for best fuel economy, regardless of where you do most of your driving.

Just try to keep engine RPM as low as you reasonably can (by not flooring the go pedal), avoid rushing into situations where you must brake, and you'll get decent results. (Thread: Rally driver gives fuel economy tips for driving the CVT Mirage (Video) .. )


>>> If the majority of your driving is on the highway

Under most cruising conditions on the open road/highway, the CVT's taller gearing keeps the engine spinning at significanly lower RPM than the manual, where it burns less fuel. [ See thread: Gear ratios: 2014 Mirage transmissions, 5-spd manual & CVT (speed vs. RPM chart) ]

Yes, there is a chance that the 5-speed could beat the CVT at highway speeds using a specific, advanced driving technique called "pulse & glide" or "burn & coast". But the technique is tedious when used repetitively, it's inappropriate to do in traffic, it's potentially dangerous for inexperienced drivers, it's illegal in some jurisdictions, and it's arguably harder on the car (mechanically) than simply cruising along at a steady speed.

So the CVT is the highway winner. (For now.... UNTIL we can convince Mitsu to offer us a proper ECO 5th gear!)


>>> If the majority of your driving is sub/urban

I would bet the manual can outperform the CVT in the hands of a competent and motivated eco-driver in sub/urban driving. (Where speeds vary, and the highest constant speed is no higher than about ~75-80 km/h / ~46-50 mph).

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UPDATE, Oct. 28 -- I've had the chance to drive both transmissions and compare mileage on the same route. As suspected, the 5-speed beat the CVT. See: Gas mileage/MPG test: 2014 Mirage CVT vs. 5-speed (sub/urban Ottawa route)

My results:

2014 Mitsubishi Mirage 1.2 L	Observed fuel economy
5-speed manual	48 mpg US (4.9 L/100 km = 20.4 km/L = 58 mpg UK)
CVT automatic *	42 mpg (US) (5.6 L/100 km = 17.9 km/L = 50 mpg UK)

See comparison test for more information.

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The manual gives the driver much more control over RPM vs. engine load (a loaded, low RPM engine generally produces power most efficiently).

Also, the ability to use neutral for coasting up to transitions (stops & turns) is easier done with a manual. Sure, the CVT can be shifted to N just as easily, but going back into gear smoothly while the car is still in motion is something the manual was specifically designed for. The CVT, possibly not, so frequently shifting in and out of gear may not be good for it (or smooth).

Using advanced techniques will futher boost city economy: eg. shutting off the engine while stopped/slowing is a big one. Only Europe & Japan get the factory "auto stop and go" feature for now. Without it, we have to do this manually. And restarting the engine and moving away smartly (ie. not holding up other drivers) is much more easily done with the manual because the engine can be re-started while the proper gear is already selected, then ease out the clutch and go. (Where the CVT must be started in N or P, then shifted to the proper gear to wait for it to engage before accelerating.)

So, IF you're motivated and skilled (or willing to learn / develop your eco-driving skills), I'd pick the manual for sub/urban duty.


>>> The CVT's payback period / "return on investment" ...

The CVT in the costs $1000 extra in the U.S. ($1200 in Canada currently). Going strictly by the U.S. mark-up and EPA ratings, and with fuel cost at $USD 3.61 per US gallon ...

If you drive exclusively on the highway (15k miles/yr.)...

	CVT @ 44 mpg	5-speed Manual @ 42 mpg
Annual fuel cost	$1231	$1289
Annual difference	-$58	+$58

Going strictly by the rating, it would take about 17 years for the CVT (at $1000 extra) to pay for itself in highway driving.

In mixed driving 45% city/55% highway (15k miles/yr. )...

	CVT @ 40 mpg	5-speed Manual @ 37 mpg
Annual fuel cost	$1354	$1464
Annual difference	-$110	+$110

And in mixed use, it would take about 9 years for the CVT (at $1000 extra) to pay for itself in combined driving.

In 100% urban driving (15k miles/yr. )...

	CVT @ 37 mpg	5-speed Manual @ 34 mpg
Annual fuel cost	$1464	$1593
Annual difference	-$129	+$129

And in mixed use, it would take about 7.8 years for the CVT (at $1000 extra) to pay for itself in combined driving.

Of course, if you drive more, or if the price of fuel increases (a pretty good bet), the payback period will be shorter. Play with the numbers here:

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

[Daox]

Very nice post Darin. This should really help out people trying to decide when they purchase their Mirage.

[m4v3r1ck]

Nah, CVT wins in every way. The problem is that the difference in price can get you enough fuel to drive for up to 2 years with the manual .... so ... the decision is yours to make.

[MetroMPG]

Ha! I know how you drive a manual, m4v3r1ck! Definitely not "eco".

I'm quite confident the 5-speed will beat the CVT in town, but only in the hands of a MOTIVATED & CAPABLE ECO-DRIVER.

Otherwise -- in the hands of a typical driver -- yes, the CVT will use less fuel.

We shall see!

[spacester]

the cvt can be put into N just as easy as a manual so dont get that point?

just put the shift lever into N and its coasting... and if i am not mistaken the CVT already go's in somewhat of a coast when you let go of the gas pedal.. *( read no ICE braking )

[MetroMPG]

the cvt can be put into N just as easy as a manual so dont get that point?

I wasn't clear... It's going back into gear while still moving that is the question... some automatics/CVT's do not re-engage very smoothly/smartly when the car is already in motion. It's never a problem with a manual (where smoothness depends on the ability of the driver).

Updated the first post with that point.

[m4v3r1ck]

I wasn't clear... It's going back into gear while still moving that is the question... some automatics/CVT's do not re-engage very smoothly/smartly when the car is already in motion. It's never a problem with a manual (where smoothness depends on the ability of the driver).

Updated the first post with that point.

That is the problem, you can put into neutral when coming to the traffic light but when you re-engage to D they don't usually likes it. I'm a lifetime manual user (20+ years) and I switch gear VERY smoothly if I may say so myself on manual so that is one thing I don't mind, switching gears as I'm used to it. CVT would be nice in asia since almost everyone is holding their phone while making calls instead of using bluetooth carkit.

[spacester]

I wasn't clear... It's going back into gear while still moving that is the question... some automatics/CVT's do not re-engage very smoothly/smartly when the car is already in motion. It's never a problem with a manual (where smoothness depends on the ability of the driver).

Updated the first post with that point.

ok never happend to me and i driven several automatics and cvt
also did it when i was test driving the mirage.. no prop

[kalifornia]

maybe one day there will be enough owners that could find a manufacturer and make a group buy of a 5th gear assuming its a fairly easy retro fit

[Mikhail]

the cvt can be put into N just as easy as a manual so dont get that point?

just put the shift lever into N and its coasting... and if i am not mistaken the CVT already go's in somewhat of a coast when you let go of the gas pedal.. *( read no ICE braking )

Automatic versions of cars usually still use the gas on N (neutral) rather than coasting on D (Drive) where there is no gas consumption.