Bilstein vs KYB Shocks: Here’s The Difference

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Mileage and time got to your OEM shocks or struts, and now you’re looking for a replacement.

Are both KYB and Bilstein a solid choice? Absolutely. How do they actually compare to each other?

Now that’s a question you can’t answer in just a few sentences. Today, I’ll be looking at their most popular shocks:

  • Bilstein 4600 and 5100
  • KYB Monomax and Gas-A-Just

For general applications, I’d recommend Bilstein 4600 shocks. This is a balanced shock for stock height SUV/light trucks, both price and performance-wise. Unless you ride a heavy-loaded truck – in that case, MonoMaxes would be better.

If you have a lifted 4WD and are looking for more offroad action: Neither the 4600, nor Monomax are optimal. The right choice would be a Bilstein 5100 kit.

For sedans/passenger cars, Gas-A-Justs will drive the smoothest.

Here’s a quick summary before my thorough review:

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Bilstein 4600
  • Balanced shock for stock height SUVs/light trucks.
  • Smoother than Monomax on light/semi-loads.
  • The best control/handling both onroad and light offroad.
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KYB Monomax
  • Similar function like B4600 – for SUVs/light trucks.
  • Rides better on heavy loads, otherwise feels too stiff.
  • More budget-friendly than Bilsteins.
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Product Image    
Bilstein 5100
  • Zinc-plating protects from offroad damage and debris.
  • Specially designed for lifted vehicles & 4WD.
  • Firm ride control, ready to tackle any rough terrain
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Product Image    
KYB Gas-A-Just
  • Direct OEM replacement, especially for Asian cars.
  • Improved handling and firm control compared to OEMs.
  • Affordable price even though they outshine other comparable sedan shocks.
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Note: With struts, it’s KYB strut assemblies all the way, just because Bilstein rather focus on shocks.

Now that we’re done with the introductions, let’s get to the real deal.

The Big Question:
KYB Monomax vs Bilstein 4600 or Bilstein 5100?

The answer to this question is actually way simpler than you’d expect.

In fact, I’m not sure why people decided to compare either the Monomax or Bilstein 4600 to the 5100 series. Seriously.

Why? Because the 5100 shocks come with lifted vehicle support and the customized valving and damping to accommodate that. This is a shock designed for modded vehicles and heavier off-road purposes.

Which is why you’ll see it loved by various 4WD crowds: from Ford F350 owners with their sets to people who go off the beaten path with their Tacoma, Jeep etc.

In short: The 5100 is not a shock emulating OEM-style performance! It’s made for exploring the extreme.

It’s a tough steel beast with zinc plating that protects the monotube body from cracking and extreme terrain stress. Firm, but not too stiff – and allowing for superior control on uneven surfaces. 

Now, if we look at the 4600 series and KYB’s Monomax…that’s where things get heated.

Both of these aim to deliver OEM performance and are mostly targeted at more casual SUV/truck owners. By casual I mean people who mainly drive on the streets, but also go for the occasional off-road adventure from time to time.

I won’t lie to you – both shocks are very close in terms of performance in general situations. However, there are a few important differences to note:

  • If you’re going to drive a half-loaded vehicle or plan to do some towing, Bilstein 4600 is a better choice.
  • On a full load, the Monomax makes more sense.

  • However – if you plan to do more offroading, just stick to Bilsteins. Way better damping/durability.

  • If you’re a hardcore OEM ride fan, KYB has always made the OEM replacement shocks.

What’s that about half-loads?

Well, Monomaxes are stiff. Seriously – they’re probably twice the stiffness of how smooth the 4600s ride. Some people prefer firmer control, but on a half-load a set of Monomax shocks can just get uncomfortable.

They do have the coolest looks among the mid-range shocks, though:

Both the 4600 and 5100 series from Bilstein come with a digressive piston design. What this really means is that they’re specifically designed to cope with uneven patches and provide superior damping if you go through rougher roads.

This will not only provide a smoother ride but in the end it’ll keep your shocks intact for longer too.

If you see someone complaining that their Monomax shocks busted after 3 years – yeah, that guy’s done a fair bit of off-road driving. Bilsteins cope better in such environment.

Bilstein 4600

Perfect for street driving and light offroad action. Smoother than KYB Monomax on half-loaded SUVs.

KYB MonoMax

Firmer, OEM-like performance. Looks cool, drives cool. Just don’t install them on lower loads.

Shocks for Sedans & Strut Assemblies

OK, so let’s end with the SUV/trucks category.

What about sedans and, you know, just your ordinary daily commuting? Well, in this case you don’t really need to shell out that much cash. Bilstein shocks will be a financial overkill.

KYB’s Gas-A-Just is your best option here. 

First reason: Compared to the Monomax or any Bilstein shock, they drive smoother. Not to mention that they’re significantly cheaper too.

Second reason: KYB is probably the best suspension manufacturer for Asian cars. The company has deals with leading car makers like Toyota.

Gas-A-Justs are nothing else than an improved OEM with better control, better cornerning and better shock life.

➥➥Struts & Strus Assemblies: KYB all the way

If you’re looking for something close to OEM rides, the KYB strut assemblies are your best choice.

Remember that struts differ from shocks by having a secondary role: they also serve as structural support to your car’s suspensions and keep your tires aligned.

To be honest, Bilstein don’t really focus on quick strut assemblies due to their target market of SUVs and pickups.

Now, KYB offers two different strut lines: Excel-G gas struts or Gas-A-Just struts.

I suggest you go for the Excel G. Gas-A-Justs can be way too stiff as struts and will send you into a whiplash if you hit a pothole or anything bumpy.

Sure, Excel-G are twintubes and might feel like older tech, but they are smoother on the road.

Or better yet – just go with a complete corner unit assembly like this one:

KYB Assembly

Best performance for the price, exact fitment from the leading OEM manufacturer. Superior cornering.

To summarize things:

➥➥ Bilstein shocks are overall more durable and better for off-road driving.

➥➥ KYB shocks are a bit better with cornering. Their corner strut assemblies are a bargain too.

➥➥ KYB are definitely stiffer – with Bilstein you will experiences a smoother, more comfortable ride overall. This is due to their digressive piston design which deals better with road uneveness and damping.

➥➥ Bilstein for heavy duty/4×4/SUV and KYB for lighter vehicles/Asian cars is a good rule of thumb.

In any case, you should pick shocks with a monotube design as they allow for better vehicle handling. I’ll explain why this matters so much a bit further into this article.

KYB vs Bilstein:
Are there manufacture differences?

If by manufacture differences you mean cheap Made in China ‘quality’, rest easy.

Both companies conduct rigorous testing on their shocks absorbers.

KYB gets the recognition of Japanese-born production. Let’s be honest, there’s a reason why Japan has dominated the automobile industry. They put out affordable, yet efficient and quality cars based on their culture of handcrafted manufacture even to this day.

KYB does the same with shocks.

On the other hand, Bilstein come from another land of auto traditions: Germany. Some people say German people have a strange sense of humor…well, Bilstein accept no jokes with how they manufacture their shocks!

In both cases, there will be nocheap outsourcing. Bilstein live up to their slightly higher price with better manufacture, however.

Also, for their higher-grade shocks – like the 5160 or 6112 shocks, they shift the manufacture to American soil.

What does better mean anyways?

There are exactly 3 things I care about when it comes to shock absorber replacements:

➥➥ Quality manufacture so I know that I won’t be changing them in 3-4 years.

➥➥ Good, firm control over the vehicle.

➥➥ Versatility: I want them to perform well in, say, off-road conditions on top of city roads.

Do both KYB and Bilstein shocks tick all the boxes?

Yes, they do. However, a pair of KYB shocks will generally stay with you for 5 years or so. Bilsteins can work as new for well over a decade if you take care of them properly.

Yes, Bilstein shocks run more expensive. However, they also last longer, provide overall increased performance, and a tighter grip on how your vehicle behaves. Especially in more extreme conditions.

A note on the technology used

As I mentioned, KYBs drive significantly stiffer compared to the smoother Bilsteins. I know some people prefer this stiffness, but generally gentler absorbers are more easy to run miles on.

The bigger difference between these two brands lies in the technology.

I spoke about the monotube design, but what does it look like?

Well, Bilstein’s 5100 Series has a typical monotube design like all Bilstein shocks.

Monotube shocks have self-adjusting, digressive valving and run on high pressure. They are an updated version over standard low pressure twin tube shocks that run on velocity sensitive valving.

Generally, monotubes help with better vehicle handling and improved responsiveness to changes in road conditions!

Bilstein shocks are usually monotube. Stick to them if you’re driving off-road.

KYBs is a decent, yet somewhat limited upgrade here. Sure, an improvement over entry-level suspension replacements like Monroe or Gabriel, but…

Bilstein raises the bar higher. Think of them as a premium improvement that masters dirt roads and bumps or potholes.

As I pointed out earlier, KYBs fare very well with cars from different Asian manufacturers. Gas A Justs are a favorite of Hyundai Elantra or any Toyota owners, for example.

In Conclusion

Both brands will give you a better shocks experience if you compare it with hard, only semi-responsive OEMs.

But there’s no doubt that Bilsteins are the more premium choice – especially for car owners who are looking into off-road driving or sports driving. If you want a more in-depth look at them, check my detailed comparison of the 4600 and 5100 series.

KYBs are a good choice for people on a budget who own a Toyota, Nissan, Hyundai…Just make sure you stick to their monotube designed shocks so you’re on the edge of technology. Because with better technology comes better control and performance, after all.

14 thoughts on “Bilstein vs KYB Shocks: Here’s The Difference”

  1. Very thorough analysis, kudos for all the research you’ve done! I’m curious what are your thoughts on Bilstein 5160. I ran 5100 on my Ram, but a local dealer namedropped the 5160 to me saying they are even better for offroad. Any thoughts?

  2. the 4600 bilsteins are the best thing i ever did for my tacoma. they ride awesome, cant even compare them to the black stocks it came with. bilstein all the way

    1. Happy to hear that, rodeoboy!

      Yeah, the 4600 series definitely deserves its reputation. I feel it’s the most balanced onroad/offroad shock out there in its price range. A part of me would be glad if they had the sleek chrome looks of the 5100 series, but oh well…

      Here’s to many more miles of happy driving with them!
      Alex

      1. Hey, great article.
        I have a 2008 Tundra, 360,000 KMS on it. Looking to replace the front struts and the rear shocks.

        I’m a contractor, typically I have 500-750LBS in the bed.

        Was looking at the KYB Strut Plus for the fronts and the Gas-a-Just shocks for the rear…..

        I’m not an aggressive driver, however I’m looking for a more poised ride and performance. Smooth is good for me.

        Any comments?
        Cheers!

        Dan

        1. Dan, sorry for the late reply!

          The KYBs you mentioned are okay-ish, to be honest. At least with your weight. I think Monomaxes might be a bit too firm with such a load. It’s either the Strut plus or a set of 4600 (more expensive, though) which should also be smooth enough on your setup.

          I’d advise you to seek further advice on the Tundra forums just in case, though. Usually Toyotas – like many Japanese cars, ride alright on KYBs as the company is Japanese too, so they have some extra testing on national automakers.

          Cheers and best regards,
          Alex

  3. Great article; just what I’m interested in. I wonder if you could offer an opinion about my situation?

    I have a2006 Toyota 4Runner. It has the X-Reas suspension. We bought the car specifically because my wife (who has increasing back difficulties) really liked the ride. My wife no longer can take off-roading and even with the X-Reas can only barely do dirt roads very slowly for short distances (jolting really hurts her). I still do forest roads and occasionally moderate trails (at slow speed).

    But at about 140,000 miles, with our second set of shocks leaking and fearing we might have to replace the entire X-Reas system, which is VERY expensive ($4 – 5K), we are looking for alternatives.

    My service person suggested KYB; specifically, the 341340 rears and the SR4130/31 front.

    Otherwise, I was considering the Bilstein 4600. But I was confused by your comment about Bilstein and struts. Are you suggesting Bilstein shocks and KYB struts or what?

    My only other vehicle issue is that the front springs are sagging a bit (~3/4″), thus losing some ground clearance which I’m noticing offroad. I’m wondering what to do about that (back to stock or raise a little more?): replacement OEM springs, a 2″ spacer lift, longer springs.

    Overall opinion?

    1. Hi Ray, and sorry about the late reply — real life got in the way.

      Just checked the serial number you mentioned – these are indeed Excel-G struts. In terms of smoothness, they’re way better than Bilstein 5100s. Compared to 4600…I don’t know much about 4Runner setups, but both the Excel G and 4600 strive to emulate OEM, so they shouldn’t be THAT different from each other.

      I searched among the 4Runner forums for some experiences with the struts you mentioned and here’s what I found:

      1) https://www.toyota-4runner.org/4th-gen-t4rs/197665-best-shocks-road-comfort.html

      Person there went with the exact same Excel G fronts, reports it was a bit stiffer than stock and the front lift went a bit too far from him. Re: your front sagging problem, maybe the Excel G springs would be enough? The guy in the thread above went for used 4WD springs to solve his issues.

      2) https://www.toyota-4runner.org/4th-gen-t4rs/265565-has-anyone-installed-kyb-strut-plus-units.html

      Again, reports of slightly stiffer ride than the XRES springs and decent front lift when installing them.

      Re: Bilsteins shocks and KYB struts, what I wanted to say is that KYB has a wider, more dedicated strut line while Bilstein focus more on shock absorbers. There’s a slight difference (in terms of composition) between struts and shocks, even though these terms get used interchangeably often.

      In my opinion, your service person was right in choosing Excel G. I’m a huge fan of Bilsteins and the 4600s in stock cases, but I’m not sure how they’ll fare in your specific situation. From what I’ve seen, Bilsteins are a bit more durable, though.

      Hope everything is OK with you and your wife. Here’s to you enjoying some nice, smooth rides! Just in case, I’d talk with an additional service person or you can ask in the 4Runner forums for someone in a similar situation.

      Be well and take care,
      Alex

  4. Re: Hello, I have a ’96 Chevrolet C3500 dually. I’ve installed a 4.5″ spindle lift and am putting 4″ blocks in the rear. My issue is shocks. The front will use OE size but has 22.5″ (semi truck) wheels with 35-in tires. My problem area will be the additional weight of that wheel setup. A Bilstein rep was very iffy about the 4600 up front. I’ve had someone else recommend the KYB Monomax, but with those I’m concerned about an overly stiff ride. Where might you weigh in on that?

    Thank you,
    David

    1. David, hi!

      Hmmm…with this setup, I’d lean more towards the Monomax too. I think with your setup, Monomaxes shouldn’t ride too stiff, to be honest. Obviously that’s just my opinion as I can’t see things directly for myself.

      I’d say speak with one or two more reps/dealerships to have a few viewpoints at hand.

      But, as I said, I’d go with the Monomaxs in your case too.

      Btw, C3500s from the mid-90s are very cool, congrats on the fine ride!
      Alex

  5. i have a 2wd 2008 titan 140k with firestone bags. I tow a few times a year and carry alot. I was thinking 4600 in the rear. But the front I want to replace the whole unit spring and all .I sKYB ok for just the front ? I am looking at staying with no lift .

    1. Hey Ray!

      I think it SHOULD be ok.

      Mixing shock brands is OK as long as you stay with the same brand in the rear, and keep the other brand only at the front.

      Here’s a quick guide on mixing shock brands just in case:
      https://www.shockwarehouse.com/news/can-i-use-two-different-shocks-on-my-car.cfm#:~:text=Yes%2C%20you%20can%20use%20two,follow%20a%20couple%20simple%20rules%3A&text=Even%20similar%20shocks%20will%20not%20perform%20optimally%20with%20another%20brand.

      As Monomaxes have a stock height application, you shouldn’t encounter any difficulties whatsoever between front/rear.

      Best,
      Alex

  6. OK folks here is a question for you….. I have a 2005 Dodge Ram 3500 Dually with a custom flatbed, Heavy!! I have had KYB on there but am thinking may Bilstein… My truck is NOT lifted. so KYB or Bilstein and if Bilstein the 4600 or 5100 series?

    I also tow a 5th wheel with a weight of 14,000 lbs. But I don’t tow it a lot and have never taken it cross country but might???

    I am open to comments, please.

    Thanks,
    Bob

    1. Hey there, Bob!

      So did you like your previous KYB, or? Were they Monomaxes or something like their usual gas shocks?

      From what I hear, I think a set of sturdy Bilstein 4600 should do the job pretty fine. I know I spent a lot of time flattering the construction and lift of the 5100, but 4600s also do some pretty good weightlifting around!

      Cheers,
      Alex

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