according to the EPA sticker, they have achieved a best-in-class 22 mpg city/28 mpg
highway/25 mpg combined for a front-drive version): torque.
"We decided to back off on horsepower to get more torque," Coleman says. Whereas
the 3.7-liter V6 delivers 270 lb-ft of torque at 4,250 rpm, the 2.5-liter I4 delivers 310 lb-ft
at just 2,000 rpm. Coleman suggests that most people—unless they're driving an RX-8 or
something—stay below 4,000 rpm.
One of the things they did during the development of the engine was to take a
European-spec CX-5 diesel, then re-tune the engine to get the sort of torque curve they
wanted for the CX-9. Then they added mass of the vehicle so that it would be approx-
imately that of the 2016 CX-9. (And here it might be appropriate to note that the curb
weight of the 2016 CX-9 is lighter than the 2015 model: for a FWD vehicle, the new is 4,054
pounds vs. 4,323 pounds for the old, or 269 pounds; for AWD, it is 4,301 pounds new, vs.
4,449 pounds old, or 258 pounds. The new engine contributes to much of that weight
reduction, as it is 132 pounds lighter than the V6.)
Because they were developing a family vehicle, one of the places they took the modified
CX-5 was to schools, where they followed moms and dads picking up their kids. Coleman
remarks, "These people were in a hurry to get to soccer practice." But they, too, were
getting on the throttle looking for torque at low rpms.
So how did they get to the 310 lb-ft at 2,000 rpm?
"Another advantage of a
four-cylinder turbo versus a
V6 is weight savings. It is 132
pounds lighter than the V6 it
replaces." Coleman
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COVER STORY