By on August 3, 2015


I’ll admit it. I haven’t used a radar detector in years. My typical method of avoiding tickets has relied on the (patent pending) Spousal Alert System, in which the wife screams at me if the car is going too quickly in proximity to one of Ohio’s finest.

Problem is, 10 years in, I have yet to find the mute button.

Plus, she doesn’t drink coffee, so the Spousal Alert System has some glitches on drives longer than four hours. A planned family reunion in northern Wisconsin, 10-plus hours from home, reminded me that an alternative was needed. Thankfully, the kind folks from K40 Electronics offered their new RLS2 radar/laser detector for review. I’m pretty sure it already saved me from a ticket or two. With an MSRP right around $400, it is priced in the ballpark of the major players in the market.

For years, the big selling point for K40 detectors has been their “Drive Ticket-Free” guarantee. They will pay your speeding ticket if you are using their detectors. I didn’t wish to test this particular perk, so I paid more attention to the other features.

Having not used a real radar in a decade or more, the GPS is new to me. If I had a long commute, this would be quite useful. It allows the user to “mark” a location for speed traps or other locations that typically would be a hazard to a speeding driver. Upon approaching the location again, the RLS2 will alert the driver, whether or not radar/laser is present.

Another cool facet is the speed monitor, which easily replaces a screaming spouse. Set a “max” speed, and the RLS2 will alert when the car exceeds it — great if you want to hit a high score, or simply if you’ve got a long day of driving through the Kentucky hills and you accidentally hit 110 mph in your minivan on a downslope.

I particularly love the Quiet Ride. This silences everything below the speed of your choosing. When I was commuting to college back in the late 1990s, I got sick of the cheapie Cobra detector blaring when I was crawling in 20 mph traffic. I simply didn’t care, so I’d shut the unit off and forget about it until traffic opened back up again. When I’m commuting with the RLS2, I set the Quiet Ride at 55 mph, and I don’t worry about it.

No, I wasn’t going to do a Youtube “unboxing” video.

When I opened the box initially, there were a couple of power cords, a windshield mount and suction cups, and the surprisingly lightweight RLS2 detector itself. I suppose I expected something a bit more substantial feeling, though it doesn’t feel cheap. Good thing it’s light, as a heavier unit would be pulling down on the windshield mounts, eventually falling off. I’d have preferred a visor mount, as I would rather have the detector out of my immediate field of vision, but the RLS2 works best as close to the glass as possible.

There are aftermarket mounts available, as it turns out. BlendMount offers options for the most popular detectors and for most cars on the market. It looks like the mount for my Chrysler van runs around $90 — ouch. But it should minimize hassles, as well as my field-of-view concern.

K40 suggests all new radar users contact their toll-free tech support line, even before purchase, to ensure the right unit is acquired. After receiving the detector, another call is advised while parked in the car to allow the consultant to work with you to fine-tune the settings to your typical driving style and roads.

Upon receiving my test unit, I called and spoke to Brian, who asked:

  • What I was driving;
  • What type of driving I do – highway, city, mix;
  • My typical driving speed;
  • My location — though if I recall, he deduced it from my area code.

He told me the out-of-the-box settings are just about right for me, though he did have me tweak the Quiet Ride setting. Easy enough — and as I mentioned earlier, I played with that setting a good bit.

I’ve been using the RLS2 for about a month, including the long trip to the land of great cheese and beer. I was alerted to X-, K- and Ka-band radar throughout my trip, and got one hit by laser thanks to the Brown County, Wisconsin sheriff’s deputy hiding on an overpass. It has been helpful, though I do have a couple of qualms about recommending it for everyone.

First, I rather dislike the button placement. This will certainly become less of an issue over time with familiarity, but right now, considering I place the unit rather high on my windshield to minimize forward obstructions, I can’t read the labels on the buttons while in my normal seating position. A low mount position would be completely unreachable, considering the deep dash of my Town and Country. If I need to mute, or adjust the Quiet Ride speed, I’m stabbing away at six buttons hoping I get the correct one. Some other competitive models have controls placed on the front face.

The ideal placement blocks my view a bit.

The ideal placement blocks my view a bit.

Secondly, despite K40’s K-band filter theoretically rejecting alerts from collision-avoidance and radar-based cruise systems, I got a bunch of strong K-band alerts in rural areas of eastern Indiana and western Ohio. After a few of these hits, I made note of the cars around me — none were new enough to have these features. I had to mute the unit several times in these areas. After talking with K40, it seems I’ve been alerted by traffic flow sensors, which they haven’t been able to filter out just yet. They tell me that their next generation of revised products should have this filter.

k40 radar

If I were to add a killer feature, I’d love to see the GPS better integrated into more features. I’d especially love to see the RLS2 switch over from highway to city filtering as I approach an urban area, rather than needing to do so manually. I’d often switch, then forget to switch back to highway after passing through.

My time with the RLS2 has been quite educational, and I’m certain I’ll keep popping it up on the windshield as a backup on long trips, but the Spousal Alert System is permanently installed, as she has features no electronics company can replicate.

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31 Comments on “K40 RLS2 Radar Detector Review...”

  • avatar
    an innocent man

    Aunt Virginia would like a word with you.

  • avatar
    Chris Tonn

    I try to avoid any Virginias of the non-West-by-gawd varieties.

  • avatar

    You don’t actually drive with all that shit hooked up, do you?

    • 0 avatar
      Chris Tonn

      For the purposes of this review (and the mentioned road trip), yes. I needed Waze on my phone for directions, and used the RLS2 for radar/laser. For normal driving, the phone is generally out of sight.

      The photo might be misleading. I sit rather high, so the phone doesn’t obstruct my view through the windscreen at all. It obstructs the view of the back forty of my dash.

  • avatar

    In 42 years, I have never gotten a speeding ticket while driving my car. Never. In all those years, I have never once used a radar detector. My weapons are 1) cruise control 2) doing my absolute best not to speed egregiously 3) good eyesight 4) paying attention behind the wheel and last, but not least, a fair amount of luck.

    I did get two speeding tickets on my motorcycle. The first was the classic small-town fu on the very first day I had my license (1973) and the second (1987) was thoroughly and completely deserved and was was the very last time I rode my motorcycle so aggressively.

    The real question is this: does using a radar detector add to situational awareness or does it impose a false sense of security on the part of the user? I tend to think it’s the latter which is why I have never used one.

    • 0 avatar
      Silent Ricochet

      False sense of security? Perhaps a little. As a radar user, I can vouch for the effectiveness of these devices; as long as you buy one of the better models and/or brands.

      On the highway, eyesight is king in making sure you stay out of trouble. Especially if you commute, you start to learn the spots that the police sit in and you look for them far before their radars and lasers can reach you. That being said, false positives, which are mentioned in this article, are brutal. I have a $200+ radar detector that alerts me to being tagged with a Laser when the sensor catches the sun the right way. It’s annoying and most of all scares the crap out of me because it usually happens on a backroad or something where a cop would never be firing a laser. This alert can’t be shut off. So, two days ago, driving on the Taconic, I get an alert for a laser. I’ve never seen a New York State Trooper use Laser before so I ignore it. Then, up ahead, I see a blue Crown Vic sitting on the side of the road, the driver’s side window open. I looked at my speedometer, 75. In a 55. Luckily he didn’t pull me over, but I was extremely frustrated because I felt like I had been tricked. Dozens of false alerts and the one that’s real, I ignore.

      That being said, Radar Detectors have saved me a lot of money. My dad, a former police officer, seriously doubted the thing. He even suggested that I turn it off or put it away one day while out to eat. I claimed that it worked well and he shook his head. On the 40 minute drive back home, it saved me twice from tickets before any of us even had eyes on the patrol car. Many times, it’ll alert you about a cop over that hill or around that bend, and that’s when it’s really beneficial. My dad was impressed by its performance and bought one.

      • 0 avatar

        My favorite trick involves being about one quarter mile back from someone traveling at the speed I want to go. Then watch for reactions. This is actually really good driving practice, no matter what speed you are going, because it trains you to be aware of situations (slowdowns, hazards or speed traps) far enough away to be able to handle almost anything. These days, I usually set my cruise at the speed limit, but the habits learned back when I drove faster still have me looking far ahead.

        I think too many detector users try to depend too much on them rather than to learn to interpret what they are revealing as part of an overall strategy of being situationally aware. These days, I find Waze to be a great help in keeping me informed of any problems beyond my line of sight.

        • 0 avatar

          Agree about Waze and watching the traffic up ahead for its behavior (and the guilty conscience brake lights). I’m quite happy to move over for faster traffic to pass me, particularly if it is a “rabbit” to go flush out any tax collectors.

  • avatar

    My daily driver has adaptive cruise control and blind spot detection. So I would assume that turning on a radar detector in my car would simply give me a continuous “hit” in the K band.

    Furthermore, all cops where I live (Maryland) use lasers. In other words, radar detectors are nigh useless, because the lack of beam scatter on laser systems mean the dang detector doesn’t generally go off until the cop has already “painted” you with his laser.

    • 0 avatar

      I literally scheduled a test drive in the first 2013 Honda Accord Touring in Northwest Ohio in order to test my Valentine One (V1)’s reaction to the radar for the Adaptive Cruise/Forward Collision Warning radar. No problems! (Dead-nutz twin to my car, but I wanted to wait until the very first “new design” bugs had been squashed in the 9th-Gen Accords, and that was a good decision on my part!)

      (I do need to get their “upgrade” — a new detector at half-price — because my windshield mounts will just not hold the thing in place for more than one minute! Valentine Research moved to a slimmer case sometime after my 1998-vintage unit was produced, and the mount angle doesn’t sit well with it! They also have a filter for the K-band pop-ups from the traffic-information devices like Chris mentioned.)

      The V1 has paid for itself a couple times over, and I would put that up against the top-line Escort unit. All the rest, including this one, IMHO, are a cut below. (Again, just MHO — no flames, please!)

      • 0 avatar

        Consider a mirror stem mount. The suction cups don’t work all that well with the new one either. Going cord free by tapping into a powered mirrors 12v is another worthwhile step.

  • avatar
    Master Baiter

    If you stay under 80 MPH on the open road, you won’t get pulled over. If you exceed 80, there are many alternatives to radar for them to catch you. That’s why I’ve never owned a radar detector.

    • 0 avatar

      Not in Ohio. Last time I was pulled over I was doing 76 right before a 70 zone on I90. (The patrolman said he clocked me before I reached the sign, where the limit was 65). After talking for a bit he let me go with a warning.

      I don’t use a detector, however. I figure that if I get pulled over I may or may not get a ticket, depending on a number of factors. But if an officer sees a radar detector, s/he’s definitely going to write a ticket.

      I have been using Waze for the last year or so, which is especially handy as one section of I90 in Northeast Ohio has an inordinate number of objects on the road.

      • 0 avatar


        That’s the thing – if you have a visible radar detector, you are GOING to get a ticket if you do get pulled over. If you are not a twerp, without a radar detector you have a sporting chance at a warning if you are polite and not doing something completely stupid. In my younger years I had an original Passport. Still got nailed a bunch of times – including one for 60 in a 55, in traffic, in the town I lived in. 4 teenagers in a nice car with skiis on the roof – doomed. Learned how to make time on the down-low and have had one single speeding ticket this century. In the absolute middle of nowhere in Montana, no less. And I travel all over the country for work. In the really bad places like OH and VA, I just don’t speed more than 5 over. And even there, a respectable middle age dude in a nicer rental car can get away with 5 or so over pretty much all day every day.

        In my state, if they are actually looking for speeders, they use laser anyway, pretty much exclusively. And they don’t do a whole lot of looking these days. In the summer, it’s such a target rich environment of out of staters that the locals mostly get a pass anyway.

        Ultimately I get my need for speed out of the way when I have to go to my office in MA. Got to love I-95 in MA, you can do 90 and there will still be a steady stream of cars passing you, and I have NEVER seen a cop pull anyone over.

      • 0 avatar

        Not 100% I was pulled over with a visible detector and another suction mount in the footwell. LEO says “I see you hid your detector when you saw me.” I said, “no, its still up there and will get back to beeping and being ignored as soon as i turn on the ignition.”
        If you want a warning, dont lie, dont be an ass, and dont be a cold fish. If they have discretion, anything you do to reduce empathy makes it easier to hose you with the fine they know is what it feels like to get.
        Mentioning to a bordering patrolman that you’re just SO happy to be out of Texas may help too.

    • 0 avatar

      The best radar detector is simply making sure there is at least one person driving faster than you are. Decide to be one of the faster, but not fastest, drivers and there will always be somebody passing that will flush out the police for you. If you are the fastest driver on the road just slow down a little and let somebody else be the bait.

      I decided on this strategy after a crackhead broke into my (then) new car to steal my radar detector, not only breaking the side window but denting the drivers door as well. Since then, zero tickets in over 20 years.

      • 0 avatar

        @Toad, I’ll second that. I haven’t used a radar detector in several years. Going less than 10 over in my part of the country ensures generally a warning and making sure that even at 8 or 9 mph over that some are still passing you.

        • 0 avatar

          Sound advise all around. I especially like Toad’s advise about being on of the fastest cars, not THE fastest.

          @tbp0701 Ohio Highway Patrol are utterly sticklers. I drive closer to the speed limit in Ohio than anywhere else.

  • avatar

    I wonder if the LIDAR scanners on my car would set it off? I’m assuming they will. Not many cars running LIDAR now, but that’s going to change.

  • avatar
    Compaq Deskpro

    My experience with my radar detector is that it works for most small town police, but is useless on the highway, where everyone has laser. The enormous amount of false positives from construction sites, intersections with emergency lights, and random who knows whats make them kind of a hassle. I have a Cobra which was <$200, so my experience probably varies.

  • avatar

    Hell I’d pull you over just because you have all that gear blocking your view out the windshield.

  • avatar

    There was a time in my life when I would have found this interesting.

    At that time, I drove like an idiot too often.

    Now, I wouldn’t see the need. Last Friday, I drove almost 800 miles in one day, from the suburbs of Sacramento to my home near Seattle. I didn’t once reach a speed where I was worried that a cop would pull me over. It’s just less stressful that way, and often safer.

    Of course, sometimes there’s the cop who pulls you over anyway, like the guy who dinged me for 9 over (and I thought I was doing 7 over) in Idaho last summer. But a radar detector wouldn’t have done a thing about him.

    • 0 avatar

      Well that’s different. You just don’t really speed. Sometimes I get so tired of being on the road, I’d like to cruise at 90. Those are the times I would need one. For various reasons, I have weighted this issue a lot and decided to not be “that guy.” Situational awareness and, well, faith, are my strategies right now. And a 80-85 moderate risk taking.

      Talking about 800 mile trips reminds me of the NYC-Chicago runs me and my then-girlfriend used to take. In our indestructible yet loud as hell two liter Jetta. Base model with no armrest, which i regretted the most. And out fights to keep me under 90 and her not under 80 so we could actually reach before crashing and burning somewhere on god forsaken 90. those were the days.

      I hear that drive is fantastic. We want to do the Portland-San Diego beach highway sometime in January, but haven’t started researching it yet in terms of feasibility and such. I know west coast too little and am determined to change that.

      • 0 avatar

        The coast highway (101 through WA and OR, 1 in most of CA) is fantastic from start to finish. But that wasn’t my drive. I was driving on I-5, the major inland highway, all the way. With the exception of about 75 miles through the Siskiyous, that’s just 800 miles of boredom. And it was hotter than you could believe that day… A/C was working great, but stepping out of the car at rest breaks was like stepping into an oven. My thermometer registered 108 in Medford, OR.

        • 0 avatar

          That’s TOO HOT!

          I enjoyed tour photo essay the other day (old cars, you had to use your cellphone). How about a photo essay next time you do (portions of) the scenic route? TTAC has been mostly successful in engaging its readers. I wonder if “great drives with photos by our readers” would be too tacky or off message. Not unlike the guy with the diesel Ram Albert!

  • avatar

    The vast majority of laser falses are caused by the laser cruise controls of Infiniti, Mazdas, and worst of all Volvos. They are left as default on…so most of the time I look up and see a Q56 coming toward me, or a “oh so safe” Volvo.

    Some good rules have come up.
    1. Eyeballs work best. I had a passenger once who whipped out some surplus Russian Field glasses. Crossing Ohio has never been easier.

    2. Use a top notch RD. This alone is worthy of a million click baits, but use a good one. I have worshiped at the altar of Mike V through big box escorts, the Passport, and now V1.

    3. The Rabbit is your friend. Let them crest hills, corners, stay back a bit…don’t be the moron in the blind spot.

    4. Laser is a fair weather threat. No cop uses it when opening the window into freezing air.

    5. Laser is also line of sight. You can see them, unlike a gotcha radar, but they compensate by using distance-he’ll be on a hill 1000 feet away as you pop up.

    6. Know your threats. Soda can sized antenna is KA, tennis ball sized is K.

    7. Don’t ever rely on a detector…it is a backup, a small change in odds. I won’t drive without.

    8. A good RD teaches you where they sit, how they act…it isn’t a “cop sensor”.

    9. If you can move your display, do it.

    10. Waze is like CB radio. I don’t find it really reliable, but it is another data point. Too many false positives. Great otherwise for traffic density, as that isn’t user generated in the same way.

    • 0 avatar

      Aiming low. I would go this way – each cop car is traceable, dispatchers know where their people are. Get into the trace system, write application to show all cops locations on map. Drive.

  • avatar

    How does radar detection help with instant on detectors?

    • 0 avatar


      i presume you mean instant on radar. cheap detectors will never even detect a burst of radar. it takes all of about 2 seconds to lock in a speed depending on distance.

    • 0 avatar

      The Escort’s and Valentine’s do well at picking up instant-on KA over the crest of a hill, etc. as they hit the car ahead of you. As Speedlaw says above, the RD is a back-up, and you should not be in the lead anyway. Wait for the young guy in the red car to whiz by.

      None of the RCMP or metro police in BC use K-band any more. They run with KA on while opposing traffic, or use laser when static.

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