Q: How come my detector doesn't go off sometimes when I drive right past a cop car?
A. Radar detectors detect radar, not police vehicles. There's a good chance the police car you passed wasn't radar-equipped (90 percent carry no radar).
Or if it was, most officers shut off the radar while they're out of the car on a traffic stop or when using it in instant-on mode. In either case, with the radar off there was no signal to detect and your detector stayed quiet.
Q: Why does my detector go off for no reason sometimes?
A. Very likely it's receiving a radar signal, but not police radar. In town, detectors frequently alert on X or K band in reaction to radar-controlled automatic door openers. On the open road, occasional Ka-band false alarms can be expected, usually caused by radar detectors in passing cars.
K-band false alarms have become a much bigger problem. Many are due to the proliferation of vehicular Blind Spot Monitoring systems. These use K-band radar and share the frequency with police radar. Another culprit is the traffic-flow radar increasingly being installed along highways by transportation departments.
Some radar detectors use GPS and software to reduce false alarms. But Escort maintains a death grip on the patents and doesn't share. Based on our experience, some of its GPS-enabled models are more likeable than others, but all are substantially better at camera detection than the competition. View these models.
Q: What's the advantage of a built in detector?
A. We've yet to have a remote (built-in) radar detector get stolen. That's something we can't say about the $29 junk detector we once left—on the floor—of a beater Honda parked, locked, in Boston's Back Bay for a few hours. Regardless of the value, if it's visible eventually some twit will smash the glass and steal it.
Another advantage is discretion. Detectors are legal in 49 states, but some cops disapprove. Get stopped by an officer like this and expect to be cited.
The best remote we've tested is the Escort Passport 9500ci. Aside from exceptional range, it has high resistance to false alarms and comes with effective laser jammers. Learn more.
Q: Does radar work if the patrol car is moving?
A. Yes and radar on the move is far more lethal than stationary radar. Most of these radars have an antenna in front, another in back, giving them front-rear coverage.
They can also track same-direction vehicles in front of or behind the rolling cruiser. Many also can target the fastest car in a pack, making it hard to hide behind slower vehicles.
Q: I've read that putting the detector up high on the windshield gives it better range. Is this true?
A. That would seem logical, but in 30 years of testing detectors we've never seen range improve by altering mounting height by a few feet.
An extra 50-plus feet might make a difference on rare occasions, but a radar detector is more affected by orientation than height. Keeping it level and pointed down the centerline of the vehicle will maximize range.
Q: I want a detector that works on batteries so I won't have to deal with the clunky power cord. Is there any reason why I shouldn't get one?
A. Choices are slim—there's one cordless in production—the Escort Solo S3, or with luck you might find one of the discontinued PNI Silver Bullet or Whistler DE1788 cordless models. Those might be okay for low-risk drivers who never stray much beyond 5 to 8 mph over the limit.
But be prepared for much lower performance in exchange for the freedom from a power cord. Especially on Ka band, even the best cordless has at least 65 percent less range than a similarly-priced corded model like the Escort Passport 8500 X50.
On the upside, low sensitivity means they won't annoy you with a lot of false alarms from vehicular Blind Spot Monitoring radar. But don't be shocked if they don't alert soon enough to avoid the Ka-band radar favored by state highway patrols.
Q: Driving in California, I've never seen anything other than Ka band be a real alert. Am I safe turning off X and K bands unless/until I leave the state?
A. Shutting off X band west of the Mississippi is fine, but doing the same on K band isn't risk-free. Although the California Highway Patrol uses Ka band exclusively, several thousand K-band radar units remain in service nationwide, some of them on the West Coast.
But if you're being pestered by K-band false alarms, in your area the risk is low enough to make the move worthwhile.
Q: On the highway, why does my detector alert sometimes when I don't see a cop car?
A. If it's an X- or K-band alert it may be an automatic door opener. Hypersensitive radar detectors can spot these from a quarter-mile away. Occasionally a weak K- or Ka-band signal might be from a radar detector in a passing car.
Another possibility is instant-on radar working traffic up ahead. With the radar on hold, the officer triggers it at close range and gets a speed almost instantly.
The windshield-mount model best able to protect against instant-on radar is the Escort RedlineXR. In tests it alerted to this type of radar from several miles away. This was two to three times the range of competing models.
Q: How come my detector doesn't alert to red light cameras?
A. If you're driving with a high-performance detector you might already be getting camera warnings without knowing it.
Until recent years most red light and speed cameras were triggered by pavement sensors. With no radar present, there was nothing to detect.
The trend now is radar-control, much cheaper to install and maintain. A detector with very high K-band sensitivity can reliably detect these cameras. For non-radar-controlled cameras, a GPS-enabled radar detector is the best defense.
In a recent test, the three models best at detecting radar-triggered red light cameras were the Escort RedlineXR, Escort Passport 9500ci and Escort Passport 8500ci Plus. (The latter two are installed models that have GPS.)
Two GPS-enabled windshield-mount models that also performed well: Escort Max 360 and the Escort iX. Neither approached the RedlineXR in range but if you're doing mostly city driving, either would be a better camera-fighter.
Q: Sometimes I drive by a cop aiming his radar gun at me and my detector doesn't go off. How come?
A. If he was peering through an aiming reticle it was a laser, not radar. The pinpoint beam is nearly impossible to detect and allows one car inside a pack to be clocked. The only defense is a laser jammer.
Jammers are illegal in 14 states, but many drivers are willing to chance a minor infraction in exchange for dodging a far more expensive speeding ticket.
Risk of exposure is minimized by the best laser jammers as they don't generate a jammer-alert tone to tip off the officer.