Auto experts at TheCarConnection.com advise those considering the 2008 Mercury Mariner Hybrid that while it offers reasonable performance, the hybrid experience is different.
Autoblog provides detailed technical notes: "the Mercury Mariner Hybrid comes with a 2.3-liter DOHC 16-valve Atkinson cycle four-cylinder engine and a permanent magnet AC synchronous motor." This source adds that the gasoline engine "produces 133 horsepower at 6,000 rpm and 124 lb.-ft. of torque at 4,250 rpm," while the electric motor "produces 70 kw @ 5,000 rpm and 330V maximum voltage," with a net result of "155 horsepower with 0-60 times comparable to a 200 horsepower V6 engine and a boost in city-driving fuel economy of nearly 75 percent." For those curious about exactly what an "Atkinson cycle" is, Motor Trend provides the following explanation: "the Atkinson cycle features a longer power than compression stroke, sacrificing power for greater efficiency—a process popular in hybrid applications." Cars.com reports that the Mercury Mariner Hybrids "run solely on electric or gasoline power, or on a combination of the two...you can drive up to 25 mph in electric mode; as in most hybrids, that happens in relative silence."
Motor Trend states that the hybrid power is transferred to the wheels using a "smooth-shifting, electronically controlled Continuously Variable Transmission (CVT)...the only available transmission on the hybrid model." According to ConsumerGuide, however, "there's no rotating belt as in a conventional CVT. Instead, the motors work cooperatively with the gas engine through a planetary gearset to provide seamless power and maximum efficiency." Jalopnik complains that "the continuously variable transmission is less a gearbox and more a complicated way to suck just that much more fun out of driving."
Fuel economy is a strong point in the Mariner Hybrid—strong enough to earn an 8 rating for performance from TheCarConnection.com. It helps that the Mercury Mariner Hybrid 2008 "continues to be a 'full' hybrid'," according to Autoblog; "this means that, unlike other 'mild' hybrid vehicles, Mariner Hybrid can run on 100 percent electric power up to about 30 mph, maximizing in-city fuel economy." According to the Milwaukee Journal-Sentinel, the Mercury Mariner Hybrid 2008 "rates 29/27 miles per gallon on the government's city/highway cycle, compared to 17/22 for the Premier" V-6 Mariner.
Edmunds notes that "AWD Mariner Hybrids have a third electric motor that provides power to the rear wheels when extra traction or acceleration is needed...but it's not a true all-wheel-drive system, so buyers who require a serious snow vehicle are advised to look at the regular gas-powered AWD Mariner instead."
The Mariner Hybrid’s handling is capable in town, but it’s no enthusiast vehicle. According to Automotive.com, an "electric power steering pump also improves steering feel. With EPS, there's a nice balance between steering assist at parking-lot speeds and decent feel on the highway. The steering tracks more steadily than before, with less adjustment or correction." ConsumerGuide adds that the 2008 Mercury Mariner Hybrid offers "moderate cornering lean, good balance, and firm, direct steering." The reviewer also notes "braking control is good, but some testers say panic stops induce too much nosedive." Of overall handling, Jalopnik "it'll do what you want it to do but in the least enjoyable and most perfunctory way possible...you're not going to brag about driving the Mariner to your friends."