Tips And Works

The RX has always been a stylish, luxuriously appointed, and smooth-riding SUV. It's not exciting by enthusiast standards, but it's popular with the marque's buyers. Since its introduction in 1998, the RX has been Lexus's bestselling vehicle, with 108,348 of these SUVs finding buyers in 2006. And what's most interesting is that almost a quarter of those were the RX400h hybrid version.

The primary purpose of a hybrid vehicle is to save gas, yet hybrid technology has made some models, such as the Honda Accord hybrid and the RX400h, quicker than their gas-only counterparts. Getting more miles per gallon and going quicker from 0 to 60 mph is the kind of thinking we like. But to discover if the RX400h luxury SUV really could be quicker, save us some money, and assuage the environmentalist in some of us, we needed a long-term test.

So in May 2005, just a month after the RX400h went on sale, Lexus dropped off a 2006 Millennium Silver example in our parking lot. Our leather-swathed and luxuriously appointed all-wheel-drive RX400h had a base price of $49,185, and we went for such options as the Mark Levinson premium audio system ($980), a heated-front-seat and headlight-washer package ($540), a cargo mat ($92), and wheel locks ($66). That brought the sticker to a hefty $50,863.

For 2007, many previously standard features on RXs - such as the leather interior, sunroof, and navigation system - are now options. That brings the base price of a 2007 AWD RX400h down to $43,295, but that's still about $3800 more than the base price of a 2007 AWD RX350.

The RX400h was popular for staffers going on long trips, owing to its expensive-feeling interior and cushy, upscale seats. It had great power for passing, lots of bins for stowing things, and luggage space that seemed uncompromised by the extra batteries housed under the rear seat for the hybrid system.

What we really wanted to know about this hybrid, of course, was how it fared at the pumps. The EPA rates the RX400h at 31 mpg in the city and 27 mpg on the highway, and we averaged 24 mpg over 40,000 miles. It's true that we have heavy feet here in Ann Arbor, so we sent the RX out to Pat Bedard in Arizona because he loves to tease every last drop of juice out of hybrids. By working at it, with no hard acceleration and making use of the regenerative braking, he managed to average 27 mpg over four months.

Assuming premium gasoline stays at $2.39 a gallon, it would take more than 91,000 miles of driving the RX400h to recoup that $3800 difference in base price compared with the RX350. That's a lot of driving. Purely on a financial basis, it doesn't make sense to pay the extra money for the RX400h, unless you're thinking it will help save the planet.

On the other side of the performance equation, the RX400h was indeed a quick SUV, turning a respectable 0-to-60-mph time of 7.5 seconds and a 15.9-second, 90-mph quarter-mile time in its initial test. But we didn't have time between acceleration runs for the steady-state cruising required to fully charge the batteries. We made sure to do this during the final test after 40,000 miles, and that made a significant difference. The 0-to-60 time dropped to 6.6 seconds - matching a 340-hp Porsche Cayenne S - and the quarter-mile to 15.2 seconds at 94 mph, only 0.2 second and 1 mph slower than the Cayenne.

We had some issues with the hybrid powertrain. The RX400h has a V-6 gas engine and three electric motors. The first motor is part of the front-wheel-drive system and fires the gas engine and acts as a generator when needed. The second aids the gas engine by adding torque to the front transaxle and can power the vehicle on its own as well as replenish the batteries as a second generator. The third is connected to the rear differential and drives the rear wheels when additional power or traction is needed.

To many drivers the transition from purely electric to gas and electric power wasn't always smooth, and the amount of added power delivered was unpredictable. Many also felt a lurch and heard a clunking sound when the gas engine kicked in when the vehicle was at a complete stop. Most drivers thought that a $50,000 Lexus should behave more smoothly.

The regenerative braking system got gripes, too. The transition from regenerative to hydraulic braking was often disconcerting because a small increase in pressure on the brake pedal might produce a huge increase in deceleration. Drivers complained that when they began to press lightly on the brake pedal, the RX seemed to surge a bit, causing the knee-jerk reaction of applying more braking than intended. This was especially apparent in city driving at moderate to low speeds. All the Lexus service guys could do was tell us, "That's just the way they work."

The RX400h required service every 5000 miles, most just oil and oil-filter changes, tire rotations, and inspections, and the bills ran from $124 to $172. The more complicated service at 30,000 miles set us back $330. We spent $1316 on routine service, which was $400 more than it cost for our long-term Cayenne S.

Interestingly, because of the regenerative braking assistance, the RX400h's pads wore down very little: we estimated that the front and rear brake pads should last well over 100,000 miles and might not need replacement for the life of the vehicle. We had to replace the original tires at 22,215 miles because they wore out. New tires set us back $764, and new wipers at 37,000 miles added $15 to our nonwarranty repairs.

After 40,000 hard miles, our RX400h showed signs of aging, with some suspension groaning over bumps and some creaking interior panels. Despite its quirks, our RX400h turned out to be a spry and fuel-efficient luxury SUV, which is a rare combination in this price segment. For some people, that will be more than enough to justify the premium over an RX350.

RANTS AND RAVES

DAVE VANDERWERP
The brakes have no feel to them and are hard to operate smoothly. Similarly, the nonlinear power delivery makes smooth driving nearly impossible.

SUSAN MATHEWS
Wow! It's hard to tell the car is even "on," it's so quiet. Only had it for the weekend, but I'm spoiled already.

JULI BURKE
My biggest complaint is the "surging" of the engine just when I'm starting to brake. All in all, this Lexus provides an oscillating ride that's annoying in everyday use.

K.C. COLWELL
The car is comfortable and quiet going down the road. The seats are great, and the important radio controls (volume and seek) are on the driver's side and are big. The brakes and the abrupt engine drag just take a little getting used to.

PATRICK BEDARD
The trip odometer shows 28.1 mpg over the past 621 miles. Part of that mileage is a 275-mile trip to Phoenix with speeds of 80-plus on the interstate. A big contributor to the excellent mileage is no air conditioning.

JOHN PHILLIPS
To Darby, Montana, and back. On slight downhill grades, I feel a trailer-hitching effect, perhaps the outcome of the motors and engine trying to figure out which dominates. Brake feel remains a problem: 3000 miles into this trip, I'm just beginning to predict pedal travel versus stopping power.

DAN WINTER
Wait, just let me get this straight: The RX400h actually costs more than the RX350?

LEXUS RX400h AWD

VEHICLE TYPE: front-engine with rear-assist motor, 4-wheel-drive, 5-passenger, 5-door wagon

PRICE AS TESTED: $50,863 (base price: $49,185)

ENGINE TYPE: DOHC 24-valve V-6, aluminum block and heads, port fuel injection
Displacement: 202 cu in, 3311cc
Power (SAE net): 208 bhp @ 5600 rpm
Torque (SAE net): 212 lb-ft @ 4400 rpm

ELECTRIC MOTORS: Type: 3-phase AC permanent-magnet synchronous powered by 30 9.6-volt nickel-metal hydride batteries

Front:

Rear

Power (SAE net):

165 bhp @4500 rpm

67 bhp @4610 rpm

Torque (SAE net):

247 lb-ft @0-1500 rpm

96 lb-ft @0-610 rpm

PERFORMANCE:

NEW:

40,000

Zero to 60 mph:

7.5 sec

6.6 sec

Zero to 100 mph:

20.9 sec

17.5 sec

Street start, 5-60 mph:

7.3 sec

7.2 sec

Standing ¼ mile:

15.9 sec @90 mph

15.2 sec @94 mph

Braking, 70-0 mph:

197 ft

188 ft

Roadholding, 300-ft-dia skidpad:

0.73g

0.71g

Top speed (governor limited):

116 mph

116 mph

EPA fuel economy, city driving: 31 mpg
C/D-observed fuel economy: 24 mpg
Unscheduled oil additions: 0 qt

WARRANTY:
4 years/50,000 miles bumper-to-bumper; 4 years/unlimited miles roadside assistance; 6 years/70,000 miles powertrain and restraint systems; 6 years/unlimited miles corrosion protection; 8 years/100,000 miles hybrid-related components

OPERATING COSTS (FOR 40,000 MILES):
Service (8 scheduled, 0 unscheduled): $1316
Normal wear: $779
Repair: $0
Gasoline (@ $2.39 per gallon): $3967

NONWARRANTY REPAIRS:
Windshield: $424
Wiper blades: $15

LIFE EXPECTANCIES (ESTIMATED FROM 40,000-MILE TEST):
Tires: 20,000 miles
Front brake pads: more than 100,000 miles
Rear brake shoes: more than 100,000 miles

WHAT BITS AND PIECES COST:
Headlamp: $509
Engine air filter: $28
Oil filter: $5
Wheel: $471
Tire: $171
Front brake pads: $62

MODEL-YEAR CHANGES:
2007: standard fabric interior; wood-trim option; larger 9-inch screen for optional rear entertainment system; optional Mark Levinson audio system upgraded to play DVDs; direct-type tire-pressure monitoring system; upgraded optional navigation system

BAUBLES AND BOLT-ONS

SPRAY-ON BRA: Shield by Dupli-Color (www.duplicolor.com; 800-247-3270) is a temporary spray-on automotive bra available in black and a translucent milky covering Dupli-Color calls clear. It's $7.99 a can and is available at many auto-parts and retail stores. The idea is to spray it on before a road trip and then wash it off after. Okay, sounds weird, we know. It took nearly two hours to tape and mask off the Lexus in preparation for the half-hour rattle-can application. The fine print on the can says, "Removal of product is recommended within three days," which implies that Shield is only good for weekend jaunts; anything longer would require another application. We learned that even light rainfall removes most of the thin, latex-like film at highway speeds.

A second dirt-road test proved that Shield is no match for small pebbles. Shield may protect against bugs, but we recommend elbow grease and a sponge, as it will take less time. Shield is, however, great for pranks. We enjoyed spraying "Honk if you're horny" on the passenger side of a Mercedes CLS550 and watching co-workers drive away clueless.

NAV-SYSTEM UNBLOCKER: We have complained ad nauseam about the so-called lawyer's screen that comes on after startup on many navigation-equipped cars. Coastal Electronic Technologies circumvents this with the $229 Ultimate Lockpick (www.coastaletech.com; 800-507-2234). After removing half the interior of the RX to access the back of the navigation unit, we plugged an Ultimate Lockpick 1 into the correct slots and then bypassed the "I agree" startup screen. The Lockpick allows full use of the navigation system while driving and unlocks the direct-dialing keypad for use with a Bluetooth phone. Still better, it converts the nav screen into a video monitor, for which you need a video source, such as an iPod or DVD player, which is then plugged into a connection in the glove box before pressing a couple of buttons. Lockpicks are available for most Toyota and Lexus vehicles and for GM's new full-size sport-utes. To allow all navigation and Bluetooth functions to be used while in motion, simply press the destination button and then press the bull's-eye in the upper left corner. A series of automated screen changes later, and the touch-screen buttons that used to gray-out while driving retain their functionality. We don't recommend driving with your head buried in the navigation screen, but we really like this product because if we had a passenger, he could enter a destination on the fly. - K.C. Colwell