3.5 DOHC V6

19 city/26 hwy


3.5 DOHC V6

18 city/24 hwy



3.5 DOHC V6

16 city/23 hwy


3.5 DOHC V6

16 city/22 hwy

3.5 turbo V6

15 city/21 hwy

To lower fuel costs and make buying fuel easier, the Toyota Sienna uses regular unleaded gasoline. The Flex Limited requires premium for maximum efficiency, which can cost 20 to 55 cents more per gallon.

The Sienna has 1.4 gallons more fuel capacity than the Flex (20 vs. 18.6 gallons), for longer range between fill-ups.

Environmental Friendliness

In its Green Vehicle Guide, the U.S. Environmental Protection Agency (EPA) rates the Toyota Sienna higher (5 out of 10) than the Ford Flex (3). This means the Sienna produces up to 16.5 pounds less smog-producing pollutants than the Flex every 15,000 miles.


An eight-speed automatic is standard on the Toyota Sienna, for better acceleration and lower engine speed on the highway. Only a six-speed automatic is available for the Flex.

Brakes and Stopping

The Sienna stops much shorter than the Flex:



70 to 0 MPH

177 feet

192 feet

Car and Driver

60 to 0 MPH

134 feet

144 feet

Consumer Reports

60 to 0 MPH (Wet)

155 feet

157 feet

Consumer Reports

Tires and Wheels

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires available on the Sienna can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The Flex doesn’t offer run-flat tires.

Suspension and Handling

For a smoother ride and more stable handling, the Sienna’s wheelbase is 1.4 inches longer than on the Flex (119.3 inches vs. 117.9 inches).

For better handling and stability, the track (width between the wheels) on the Sienna is 2.3 inches wider in the front and 2.3 inches wider in the rear than on the Flex.

For better maneuverability, the Sienna AWD’s turning circle is 3.3 feet tighter than the Flex’s (37.4 feet vs. 40.7 feet). The Sienna’s turning circle is 3.2 feet tighter than the Flex’s (37.5 feet vs. 40.7 feet).


The design of the Toyota Sienna amounts to more than styling. The Sienna has an aerodynamic coefficient of drag of .3 Cd. That is significantly lower than the Flex (.36) and many sports cars. A more efficient exterior helps keep the interior quieter and helps the Sienna get better fuel mileage.

Passenger Space

The Sienna offers optional seating for 8 passengers; the Flex can only carry 7.

The Sienna has 8.6 cubic feet more passenger volume than the Flex (164.4 vs. 155.8).

The Sienna has 3.1 inches more front hip room, 6.6 inches more front shoulder room, 11.1 inches more rear hip room, 6.5 inches more rear shoulder room, 3 inches more third row legroom, 9.2 inches more third row hip room and 10.3 inches more third row shoulder room than the Flex.

For enhanced passenger comfort on long trips the Sienna’s middle and third row seats recline. The Flex’s third row seats don’t recline.

Cargo Capacity

The Sienna’s cargo area provides more volume than the Flex.



Behind Third Seat

39.1 cubic feet

20 cubic feet

Third Seat Folded


43.2 cubic feet

Third Seat Removed

87.1 cubic feet


Second Seat Folded

117.8 cubic feet

83.2 cubic feet

Max Cargo Volume

150 cubic feet

83.2 cubic feet

A low lift-over cargo hatch design makes loading and unloading the Sienna easier. The Sienna’s cargo hatch lift-over height is 23.6 inches, while the Flex’s liftover is 30.5 inches.

The Sienna’s cargo area is larger than the Flex’s in almost every dimension:



Length to seat (3rd/2nd/1st)



Max Width



Min Width







The Sienna’s standard towing capacity is much higher than the Flex’s (3500 vs. 2000 pounds).


The Sienna’s front and rear power windows all open or close fully with one touch of the switches, making it more convenient at drive-up windows and toll booths, or when talking with someone outside the car. The Flex’s rear power window switches have to be held the entire time to open or close them fully.

The Sienna has a standard locking fuel door with a remote release located convenient to the driver. A locking fuel door helps prevent vandalism, such as sugar in the tank and fuel theft. The Flex doesn’t offer a locking fuel door.

Consumer Reports rated the Sienna’s headlight performance “Very Good,” a higher rating than the Flex’s headlights, which were rated “Good.”

While driving with high beams on, sensitive light sensors standard on the Sienna detect other vehicles which could be blinded and automatically switch to low beams. The Flex doesn’t offer automatic dimming high beams.

When the Sienna Limited is put in reverse, both rearview mirrors tilt from their original position. This gives the driver a better view of the curb during parallel parking maneuvers. Shifting out of reverse puts the mirrors into their original positions. The Flex’s mirrors don’t automatically adjust for backing.

The Sienna Limited has standard automatic dimming rear and side view mirrors which automatically darken quickly when headlights shine on them, keeping following vehicles from blinding or distracting the driver. The Flex has an automatic rear view mirror, but its side mirrors don’t dim.

The Sienna has a standard dual zone air conditioning allows the driver and front passenger to choose two completely different temperatures so people with different temperature preferences won’t have to compromise. This makes both the driver and front passenger as comfortable as possible. Dual zone air conditioning is only available on the Flex SEL/Limited.

Economic Advantages

According to The Car Book by Jack Gillis, the Sienna is less expensive to operate than the Flex because typical repairs cost much less on the Sienna than the Flex, including $430 less for a muffler, $1 less for front brake pads, $11 less for front struts and $115 less for a power steering pump.


Consumer Reports? recommends the Toyota Sienna, based on reliability, safety and performance. The Ford Flex isn't recommended.

Consumer Reports performed a comparison test in its September 2010 issue and they ranked the Toyota Sienna XLE first. They ranked the Ford Flex Limited AWD third.

The Toyota Sienna outsold the Ford Flex by over four to one during 2018.

© 1991-2018 Advanta-STAR Automotive Research. All rights reserved.

How much is your car worth?

Get the best value for your car from an Asbury dealership.

Featured Videos