Escape Hybrid Surprise
One-on-one dialog with Sherif Marakby, the Chief Engineer of Ford's Escape Hybrid program.
By Bill Moore
My first impression on seeing the green 2008 Ford Escape Hybrid wasn't all that positive, frankly.
Here was another big, bulky SUV that while attractive, probably wasn't going to be all that exciting or surprising to drive. I had tested the 2005 model on a marathon excursion to Minneapolis and back in the same day and found that I wasn't comfortable driving it more than 65 mph from a safety perspective; thoughts of exploding Firestone tires and deadly rollovers still lurked in the darker recesses of my mind.
Besides, anywhere above 65 mph, my fuel economy plummeted as I tried to push ever-heavier masses of air out of my way. Two things though had impressed me about the '05 model: its GPS navigation system and its ability to cruise along in Minneapolis rush hour traffic in electric mode-only with the gasoline engine turned off.
Now here I was more than two years and nearly two thousand miles away rolling down the 101 south of San Francisco International Airport on my way to Google's corporate campus in Mountain View; at times creeping along at less than 20 mph and at other times racing at 55-60 mph, and all the while the fuel economy display kept gradually edging its way higher and higher.
When I picked up the car, which Ford had arranged to have left for me near SFO, the previous driver had gotten somewhere around 27-28 mpg, not shabby for any SUV, but not particularly remarkable either since I had seen similar numbers in the '05 version.
As I motored down the peninsula, visiting first Google and then Tesla Motors, my initial impression of this rolling shipping container began to fade, and by the time I was crossing the San Mateo bridge late in the afternoon, I was a convert. Ford engineers had clearly refined and improved this second generation hybrid, especially its fuel economy. As the gray-green waters of San Francisco Bay swept beneath me, the fuel economy was showing 36.1 mpg and I was rolling along at better than 60 mph.
During my several days with the Escape, I put somewhere over 200 miles on the vehicle in both rush hour -- meaning stop and go with lots of electric-only motoring -- and off-peak driving including a run over to Woodside for a wonderful dinner meeting with Lightning Motor's developer Richard Hatfield at Buck's Restaurant where Silicon Valley venture capitalists dine amidst a collection of funky memorabilia hanging from the walls and ceiling.
It was while driving back across the San Mateo bridge on the way to a morning meeting with CalCar's Felix Kramer that I decided rather than write the usual review of the vehicle, I would contact Ford and talk with the program's Chief Engineer, Sherif Marakby, to find out what his team had done to improve the '08's performance so dramatically; I mean, I don't even get 36 mpg in my 4-cylinder Honda Accord.
You can listen to our conversation in its entirety using either of the two MP3 players at the top of the page, or by downloading the 6.45MB file to your computer hard drive for transfer to and playback on your favorite MP3 device.
IN BRIEF: Synopsis of Sherif Marakby Interview
Marakby explained that since the roll-out of the first generation Escape Hybrid, his team of engineers have focused on refining the computer control system in their second generation drive. The result is not only improved fuel economy, but also a smoother, almost imperceptible transition from electric-drive to gasoline engine. Much of the work they did is also on better managing the energy flow between the battery and electric motors.
He commented that other customers are reporting similar performance with mileage numbers in the low-to-mid 30s in mixed city/highway driving. This also translates into approximately a $500 increase in the U.S. federal tax credit on Ford's hybrid vehicles.
While it might appear that fuel economy between the '05 (36/31 prior to EPA revision) and '08 models (34/30 after EPA revision) has suffered, my 200 mile test drive around the Bay Area seems to illustrated two things: the EPA's old fuel economy measurement system grossly over-estimated real world fuel economy -- on conventional cars and hybrids alike -- and it now appears to slightly under-estimate it, which is probably the better of the two since it can result, as I discovered, in a very pleasant consumer experience.
In addition to tweaking the aerodynamics of the 2008 model, Ford also found little ways to lighten the base vehicle while adding features not found on the 2005; the end result being a vehicle that weighs essentially the same as the original model. (3638 vs. 3627lbs/1650 vs.1645kg, 2008/2005 FWD respectively.)
Added to the '08 is a dual zone climate control system, along with improving the hybrid mode air conditioning system. Steering and handling have been improved, as well, Marakby noted. Additional sound deadening material was also added to reduce interior road noise.
Work on improving the 2008 over the 2005 model began even before the first Escape Hybrid went on sale to Ford customers. Program engineers starting getting feedback from early test drives, including their likes and dislikes, along with questions of durability. Data and customer feedback continues to come back to Ford from its dealers on a daily basis, which is fed directly to its hybrid program engineers.
The '08 model integrates the Generation II version Sanyo nickel metal hydride battery pack, along with improved electronics and control circuitry. On the cell-side, Sanyo has improved the internal efficiency of the cell so that the power in/out ratio has been improved, along with the amount of power coming from the cell.
In order to refine the transition from electric to hybrid, along with fuel economy, Ford engineers have to literally take into account hundreds of different factors when optimizing the system. The effort has garnered the company some 200 patents in the control system area alone.
The company's experience to date with the durability of its NiMH battery pack also has been encouraging. Several taxi cab fleets operating the Escape Hybrid now have vehicles with more than 200,000 miles on them without seeing any problems. Consumers are also seeing few issues with their battery packs.
In collaboration with Southern California Edison (SCE), Ford is beginning to experiment with lithium ion batteries in a small fleet of Escape Hybrids, which will be converted by Ford to plug-in hybrids as part of a three-year research program to better understand the issues with grid-rechargeable, hybrid vehicles. Marakby would not, however, discuss who is providing those batteries, though he said that the company continues to investigate other promising chemistries, technologies and manufacturers. He predicted that we will see lithium-powered hybrid vehicles "within the next three-to-five years."
The biggest single improvement in the '08 model over the previous verison is, in Marakby's words, its "refinement", especially in terms of the "drive experience" and interior quietness.
Coming back to the SCE plug-in hybrid collaboration, Marakby noted that the two chief areas of concern are vehicle emissions and crash safety. Research done by Argonne National Labs seems to indicate the cold start emissions on converted plug-in hybrids are higher than on conventional hybrids. This needs to be addressed. Also, there are concerns about the location of the additional battery pack within the vehicle crush zone that could endanger passengers and emergency first responders in an accident.
A third area of concern is optimal fuel economy, which Marakby notes isn't always when the gasoline engine is off; touching on the "blended hybrid-mode" debate. Here the question is raised to as which is more efficient, running a PHEV for 40-60 miles on electric only and then turning on the gasoline engine to both propel the car and recharge the battery or running the IC engine more often, but for shorter periods of time, keeping the battery happier and the catalytic converter warm.
The fourth question the collaboration will seek to answer is the one of durability both in terms of mileage and calendar life.
Beyond its small test fleet of flexible-fuel Escape Hybrids that is scattered across the U.S. -- he didn't reveal the exact number or their locations -- Marakby said that, at the moment, Ford has no plans to offer flexible fuel (E-85 ethanol) versions of the Escape Hybrid to retail customers.
The Fusion Hybrid now in development will have Ford's third generation drive system, and while he wouldn't share what that means in terms of its CAFE ratings, he did indicate that it will likely go on sale in late 2008. He did hint that there are some "surprises" in store when it does.
You can listen to the entire 27-minute conversation with Sherif Marakby using either of the two MP3 players at the top of the page or by downloading the file to your computer hard drive for transfer to and playback on your favorite MP3 device.