VR World: K40 RL100 Radar Detector Reviewed – Simple, Easy and Mostly Effective

December 23, 2013

Categories: Reviews8.5 min read
k40 review vr logo

When it comes to radar detectors, most people have absolutely no idea what to look for. The truth is that many radar detector manufacturers make some pretty grandiose claims and have countless features that most people really have no use for.

The K40 RL100 radar detector has a few interesting features that make it a no-frills high-performance radar detector. It has 12 customizable settings so that you can adjust the radar detector to your own preferences based on sensitivity, brightness, and volume. It has a Quiet Ride feature which allows you to set a certain speed at which the radar detector will be silent and above that speed, it will alert you as needed. The Speed Monitor feature gives the driver an audible alert if they go over a certain pre-set speed telling them to slow down. This feature could be used by a lot of people that forget how lead-footed they can be at times. You can also use a fully programmable laser/radar alert option to eliminate false positives from parking assist systems and neighborhood speed detectors.


The K40 RL100 also has a variable tone alert system which at first notifies you loudly of a potential frequency and then reduces the tone if it remains constant as to not to annoy you. It also has a variable brightness LED display that can either be in day mode, night mode or entirely off depending on a users’ preference.

In terms of the radar detector, the left-hand side of the device has the power plug and the volume/on-off switch and the right side is completely free of any buttons. Considering that most drivers sit to the left of the radar detector, this is a solid design choice. The four buttons on the top function the most on the device enabling various features mentioned above.

The RL100 also has Immediate Frequency Rejection Software built into the device in order to reduce false alarms from things like garage door openers, cellular towers, bank alarms, and other non-police transmitters that could create a false positive. And if you manually set up the RL100 to your own personal preferences you don’t have to worry about it losing them because it has built-in memory and battery to remember your settings. It also auto-calibrates and self tests every time you turn it on, in the event that something isn’t quite right.

In terms of accessories, you get a pretty standard set of power cables with one really long 12v power cable and a shorter coiled 12v power cable, both ready for car use. It also comes with a pair of suction cups that attach to a brace that slides into the radar detector for mounting. once mounted, the two suction cups attach to the windshield of the car.

Now, K40 supports their products, including the RL100 with a 100% ticket free guarantee, which will cover any speeding tickets that you get in the first year even while using the RL100 as long as you register the radar detector within the first 30 days of ownership. They do state, however, that they will not cover any tickets in construction zones, school zones, or in connection with a DUI/DWI. They also guarantee that you will be 100% satisfied in terms of performance and offer a 30-day money-back guarantee.

In addition to these guarantees, they have amazing support, which the people from K40 recommended we try. Our experience with calling them was an incredibly pleasant one because K40 believes in supporting the customer to make their purchase, during their purchase, and after their purchase. This well-rounded customer service approach is sure to attract customers that expect quality and good support. The wait time for my call was a short and sweet 5 minutes and the gentleman with whom I spoke was incredibly helpful and informative. If I had been in the market for an RL100 or the more encompassing RL360 I think that he alone would have sealed the deal. It was really nice talking to someone so casually about the questions I had about the radar detector without feeling like I was talking to someone who didn’t know anything or being talked down to.

In order to test the K40 RL100, we took it with us on the road when we drove up to a conference in the Bay Area all the way from San Diego. This would mean that we would get a solid amount of freeway and city driving and a total of about 900 miles of testing and 12 or so hours of driving.

During the course of our travels, the only disappointing thing was that the suction cups of the RL100 seemed not to stick very well to my windshield. I would definitely advise making sure that the windshield and suction cups are absolutely clean and that you use the non-coiled cable for longer trips. Hilariously enough almost the entire trip up to San Francisco there were very few police or CHP (California Highway Patrol). But based on our estimations of the trip up and down we were only able to detect 50% of police and CHP and this is not due to the radar detector’s failures. This is simply because of the number of officers that simply turn off their vehicles and all of their equipment to prevent detection. As such, anyone that looks to rely 100% upon a radar detector simply cannot. A radar detector is a preventative tool, but not necessarily a fool-proof one. If you choose to drive at a high speed and want to avoid detection you must always be vigilant.

Additionally, on the trip back we were able to test out the laser feature as one of the officers in Ventura lasered us on the 5 South freeway. With lasers, the ability to reduce speed before detection is much lower and you only have but a few seconds to reduce your speed before a lock is obtained. Thankfully in our case, we were going the legal speed limit and there was no concern of a speeding ticket.

The K40 is also a great tool for measuring the accuracy of a car’s speedometer or a phone’s GPS. Overall, the K40 provided the most consistent and accurate results and actually sat somewhere between the car and the phone’s GPS in terms of speed accuracy.

On the way down the 5 from San Francisco, I also discovered something that was a bit perplexing and was then later explained to me by the people at K40. As I came close to some vehicles, I thought that they were actually police vehicles, but clearly, they weren’t. The false positives were a result of the fact that newer luxury cars have a collision-avoidance system as part of their safety vehicle packages. This is a system that works with K-band radar emitters in the vehicle to detect the distance of the vehicle ahead of them and if necessary apply the brakes automatically to prevent an accident or warn the driver of an imminent collision. Because they are true K-band radar emitters, they will set off a radar detector.

Now, in terms of radar bands, there are three blocks of bands that the police are allowed to use by the FCC. Those are the X band, K band, and Ka-band, all of those bands are supported by the K40. The X band runs between 10.5 and 10.55 GHz, the K band operates between 24.050 GHz and 25.250 GHz and the Ka-band operates between 33.3 GHz and 36 GHz. Obviously, then, you can expect that the majority of results will be within the K and Ka bands, with very few operating within the razor-thin X band. And based on our experience with the K40 RL100 this seems to be quite true with the X-band being the least frequent.

K40 did a test of the RL100 against some competitors’ solutions and claims an ability to measure up to 9 miles away. In my experience, that was much lower with an effective range of about a half-mile to a mile depending on the conditions. Admittedly, this was on the highway setting, which is the most sensitive, but it is also the most useful when going high speeds. In most cases, I was able to appropriately detect the vehicle after getting a notification on the RL100, in most cases, the visual identification was merely a confirmation of the RL100’s detection.

On the drive up my passenger, Mr. Marcus Pollice accidentally engaged the GPS notification feature of the RL100 when setting it up (a possible thing they could fix to prevent accidental GPS tags). Interestingly enough, this feature also worked perfectly as we had forgotten that we had enabled the notification feature, to begin with. But in all seriousness, I think it should take a little bit more than a single short press to engage a GPS notification spot.

In terms of price, the K40 RL100 is not a cheap device. It currently retails on Amazon for $369.99 and comes with a one year warranty but will not be warrantied unless purchased through an approved dealer. They also sell K40 directly through approved installers and retailers. Considering that most decent radar detectors fall within this price range, the $369.99 price comes as no surprise. And if you’re planning on being a bit lead-footed, such a radar detector would pay for itself with the first avoided ticket or even the first ticket you get with it if you make a claim with K40’s ticket paying policy. Essentially, this becomes a sound investment for anyone that speeds, even a bit. After all, speeding tickets, especially in states like California are only getting more expensive.

Overall, my experiences with the RL100 were very positive and I would highly recommend it to others as a no-frills solid radar detector solution. As I learned during my months of use, there is no replacement for vigilant driving, not even a high-end radar detector. One can use a good radar detector to assist in safe driving, but it does not mean that you can drive irresponsibly and expect not to get a ticket. A good radar detector is an effective tool but not the end all be all.

By Anshel Sag

Original Article

Share This Story, Choose Your Platform!

Browse Topics