The 1 Series offers optional BMW Assist, which uses a global positioning satellite (GPS) receiver and a cellular system to get driving directions, remotely unlock your doors if you lock your keys in, help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The IS Series doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies.
Both the 1 Series and the IS Series have standard driver and passenger frontal airbags, front side-impact airbags, head airbags, front seatbelt pretensioners, four wheel antilock brakes, traction control and electronic stability systems to prevent skidding.
The 1 Series’ corrosion warranty is 6 years longer than the IS Series’ (12 vs. 6 years).
BMW pays for scheduled maintenance on the 1 Series for 4 years and 50,000 miles. BMW will pay for oil changes, tire rotation, lubrication and any other scheduled maintenance. Lexus doesn’t pay scheduled maintenance for the IS Series.
There are over 73 percent more BMW dealers than there are Lexus dealers, which makes it much easier to get service under the 1 Series’ warranty.
The 128i’s standard 3.0 DOHC 6 cyl. produces 26 more horsepower (230 vs. 204) and 15 lbs.-ft. more torque (200 vs. 185) than the IS250’s standard 2.5 DOHC V6. The 135i’s standard 3.0 turbo 6 cyl. produces 23 lbs.-ft. more torque (300 vs. 277) than the IS350’s standard 3.5 DOHC V6.
For more instantaneous acceleration and better engine flexibility in any gear, the 1 Series’ engines produce their peak torque at lower RPM’s than the IS Series:
Torque |
|
128i 3.0 DOHC 6 cyl. |
2750 RPM |
135i 3.0 turbo 6 cyl. |
1400 RPM |
IS250 2.5 DOHC V6 |
4800 RPM |
IS350 3.5 DOHC V6 |
4800 RPM |
On the EPA test cycle the 128i Manual gets better fuel mileage than the IS250 RWD Manual (18 city/28 hwy vs. 18 city/26 hwy).
For better stopping power the 1 Series’ brake rotors are larger than those on the IS Series:
128i |
135i |
IS250 |
IS350 |
|
Front Rotors |
11.8 inches |
13.3 inches |
11.65 inches |
13.15 inches |
Rear Rotors |
11.8 inches |
12.8 inches |
11.45 inches |
12.2 inches |
The 1 Series’ standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs standard on the IS250 are solid, not vented.
The 135i’s 245/35R18 rear tires provide better handling because they have a lower 35 series profile (height to width ratio) which provides a stiffer sidewall than the IS Series’ optional 40 series tires.
Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires standard on the 1 Series 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 1 Series is 8.4 inches shorter than the IS Series, making the 1 Series easier to handle, maneuver and park in tight spaces. The 1 Series is 8.4 inches shorter than the IS Series.
The 1 Series Coupe has 1.6 inches more front shoulder room, .2 inches more rear headroom and 2.3 inches more rear shoulder room than the IS Series.
The 1 Series’ standard rear seats fold to accommodate long and bulky cargo. The IS Series doesn’t offer folding rear seats, only a ski pass-through.
The 1 Series’ 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.
Heated windshield washer nozzles are standard on the 1 Series to prevent washer fluid and nozzles from freezing and help continue to keep the windshield clear in sub-freezing temperatures. The IS Series doesn’t offer heated windshield washer nozzles.
The 1 Series’ available GPS navigation system has a real-time traffic update feature that offers alternative routes to automatically bypass traffic problems. (Service available in a limited number of metro areas.) The IS Series’ available navigation system doesn’t offer real-time traffic updates.
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