Compare the2018 Infiniti Q50VS 2018 Lexus IS Series

Over 200 people are killed each year when backed over by motor vehicles. The Q50 (except Pure) offers optional Back-up Collision Intervention which use rear sensors to monitor and automatically apply the brakes to prevent a rear collision. The IS Series doesn’t offer backup collision prevention brakes.

The Q50 (except Pure) offers an optional Around View® Monitor to allow the driver to see objects all around the vehicle on a screen. The IS Series only offers a rear monitor and front and rear parking sensors that beep. That doesn’t help with obstacles to the sides.

Both the Q50 and the IS Series have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, rearview cameras, available all-wheel drive, crash mitigating brakes, lane departure warning systems, blind spot warning systems and rear cross-path warning.

The National Highway Traffic Safety Administration does 35 MPH front crash tests on new vehicles. In this test, results indicate that the Infiniti Q50 is safer than the Lexus IS Series:

New test not comparable to pre-2011 test results. More stars = Better. Lower test results = Better.

The National Highway Traffic Safety Administration does side impact tests on new vehicles. In this test, which crashes the vehicle into a flat barrier at 38.5 MPH and into a post at 20 MPH, results indicate that the Infiniti Q50 is safer than the Lexus IS Series:

New test not comparable to pre-2011 test results. More stars = Better. Lower test results = Better.

The Q50 comes with a full 4-year/60,000-mile basic warranty, which covers the entire car and includes 24-hour roadside assistance. The IS Series’ 4-year/50,000-mile basic warranty expires 10,000 miles sooner.

The Q50’s corrosion warranty is 1 year longer than the IS Series’ (7 vs. 6 years).

The Q50 has more powerful engines than the IS Series:

As tested in Motor Trend the Q50 Hybrid 3.5 DOHC V6 hybrid is faster than the IS 350 3.5 DOHC V6:

On the EPA test cycle the Q50 Hybrid gets better fuel mileage than the IS Series:

On the EPA test cycle the Q50 gets better fuel mileage than the IS Series:

Regenerative brakes improve the Q50 Hybrid’s fuel efficiency by converting inertia back into energy instead of wasting it. The IS Series doesn’t offer a regenerative braking system.

In heavy traffic or at stoplights the Q50 Hybrid/2.0t’s engine automatically turns off when the vehicle is stopped, saving fuel and reducing pollution. The engine is automatically restarted when the driver gets ready to move again. (Start/Stop isn’t accounted in present EPA fuel mileage tests.) The IS Series doesn’t offer an automatic engine start/stop system.

The Q50’s standard fuel tank has 2.6 gallons more fuel capacity than the IS Series (20 vs. 17.4 gallons).

For better stopping power the Q50 Sport’s front brake rotors are larger than those on the IS Series:

The Q50 stops much shorter than the IS Series:

For better traction, the Q50 Red Sport 400’s tires are larger than the largest tires available on the IS Series (F:245/40R19 & R:265/35R19 vs. F:225/40R18 & R:255/35R18).

For better ride, handling and brake cooling the Q50 offers optional 19-inch wheels. The IS Series’ largest wheels are only 18-inches.

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires available on the Q50 can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The IS Series doesn’t offer run-flat tires.

The Q50’s optional drift compensation steering can automatically compensate for road conditions which would cause the vehicle to drift from side to side, helping the driver to keep the vehicle straight more easily. The IS Series doesn’t offer drift compensation steering.

For a smoother ride and more stable handling, the Q50’s wheelbase is 2 inches longer than on the IS Series (112.2 inches vs. 110.2 inches).

The Q50 handles at .95 G’s, while the IS Series AWD pulls only .81 G’s of cornering force in a Car and Driver skidpad test.

The Q50 executes Motor Trend’s “Figure Eight” maneuver 1.6 seconds quicker than the IS Series (25.5 seconds @ .76 average G’s vs. 27.1 seconds @ .65 average G’s).

To almost totally eliminate engine vibration in the passenger area, the Q50 has liquid-filled engine mounts. The liquid helps further dampen engine harshness. The IS Series uses conventional solid rubber engine mounts.

Because it has more passenger and cargo room, the Q50 is rated a Mid-size car by the EPA, while the IS Series is rated a Compact.

The Q50 has 11.3 cubic feet more passenger volume than the IS Series (101.5 vs. 90.2).

The Q50 has 2 inches more front headroom, .8 inches more front shoulder room, .6 inches more rear headroom, 2.9 inches more rear legroom and 2.7 inches more rear shoulder room than the IS Series.

The Q50 has a much larger trunk than the IS Series (13.2 vs. 10.8 cubic feet).

J.D. Power and Associates surveys of service recipients show that Infiniti service is better than Lexus. J.D. Power ranks Infiniti first in service department satisfaction. With a 5% lower rating, Lexus is ranked third.

The Q50’s rain-sensitive wipers adjust their speed and turn on and off automatically based on the amount of rainfall on the windshield. This allows the driver to concentrate on driving without constantly adjusting the wipers. The IS Series’ standard manually variable intermittent wipers have to be constantly adjusted.

Consumer Reports rated the Q50’s headlight performance “Good,” a higher rating than the IS Series’ headlights, which were rated “Fair.”

To shield the driver and front passenger’s vision over a larger portion of the windshield and side windows, the Q50 has standard extendable sun visors. The IS Series doesn’t offer extendable visors.

According to The Car Book by Jack Gillis, the Q50 is less expensive to operate than the IS Series because typical repairs cost much less on the Q50 than the IS Series, including $233 less for an alternator, $487 less for a starter, $228 less for fuel injection and $588 less for a timing belt/chain.

Consumer Reports performed a comparison test in its December 2013 issue and the Infiniti Q50 AWD won out over the Lexus IS Series AWD.

The Infiniti Q50 outsold the Lexus IS Series by 54% during 2017.