You’d be surprised how often I get asked about these three shocks and their differences. I mean, it’s expected – each of them is considered a KYB flagship product.

People don’t compare MonoMax to Excel G, they’re too different. However, I do get queries about KYB Gas-A-Just vs MonoMax on one hand; and the Gas-A-Just vs Excel G on the other.

If you’ve been having the same thoughts, this in-depth post is for you.

I know some of you are busy, though. So before the charts and paragraphs, here’s a quick overview of where each shock excels:

Generally, in terms of ride feel you’re looking at KYB MonoMax > Gas-A-Just > Excel G lined up from stiffer to softer damping.

There’s one important catch here, though. Let’s look at it before I compare the Gas-A-Just vs MonoMax first, and then the Gas-A-Justs vs Excel G.

Most people know what damping is (and how it feels).

Some don’t realize that damping itself is a combination of compression and rebound cycles. Without being too technical:

• Compression deals with bump/road imperfection absorption when your wheel moves upwards to tackle the irregularities. Higher compression means less body roll and better control at higher speeds or harsher terrain.
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• Rebound is the process of the suspension returning back to its initial position after the bump/road imperfection has been met. Higher rebound rates again mean less body roll, but they also mean your shock will be ready to compress again faster.

That said, here are the overall damping rates of the three KYB shocks. I’ve used stock (OEM) shock absorbers as the 100% baseline:

In other words, KYB goes from +40% on MonoMax, to +25% on Gas-A-Just to ~10% on Excel G.

However, as I said, there is a catch. Technically, the MonoMax shocks will ride harsher due to its increased compression + rebound rates.

Things change when you factor in how loaded your vehicle is, though. On empty loads, a MonoMax will ride noticeably stiffer than any either KYB. On heavy loads, however, any Excel G will rattle and even Gas-A-Justs won’t feel as smooth.

Additionally, with anything else except MonoMax, you risk component damage. There’s a moderate chance that road bumps/potholes will cause your axle to hit the frame when hauling heavier loads.

Why higher-end?

Well, it all starts with the shock body design. Unlike the twin-tube Excel G, both the MonoMax and Gas-A-Just are monotube shock absorbers.

Basically, you have two separate chambers: one for the gas (nitrogen) and one for the hydraulic fluid. This design approach vastly improves damping capabilities and prevents any aeration.

The monotube design and the larger tire support is where the similarities between Gas-A-Just and MonoMax end.

First of all, KYB MonoMax is fully equipped to deal with towing trailers or extreme terrain. This readiness is a mix of reinforced construction (zinc-coated piston ring), dust boots to deal with gravel/dirt, and improved oil diffusion.

Furthermore, some MonoMax applications fully support lifted vehicles.

Gas-A-Justs are mainly aimed at stock-height vehicles and more specifically – light trucks or SUVs/crossovers.

That said, Gas-A-Justs have slightly more travel than the MonoMaxes.

As I noted earlier, there is a significant difference in how these two shocks are calibrated. A difference between 25% firmer damping than OEM and 40% is quite significant; especially on unloaded vehicles.

Put the MonoMax on any heavy-duty truck that you want to use for towing, modifications, or extreme terrain traversing. The heavy-duty construction and several design perks totally make a difference.

Leave the Gas-A-Justs for stock vehicles with larger tires that need a more controlled ride than OEM. If you have a light truck that doesn’t haul much, Gas-A-Just will be better too. The MonoMax will ride too stiff on emptier vehicles.

I realize why people compare these two shocks, but I still feel they’re too different.

As I mentioned earlier, the first big difference lies in the design.

Excel G are twin-tube shocks, much like most OEM shock absorbers. They don’t deal as well with heat dissipation and the smaller piston means you get subpar damping compared to the monotube Gas-A-Just.

Furthermore, while Gas-A-Justs support larger wheels or tires, Excel G can’t handle anything more than stock tires.

In all other aspects, KYB Gas-A-Just takes the core Excel G features and takes them up a notch. Both shocks feature improved steering response, cornering capabilities, and rear support to enhance your brake performance.

If you want your vehicle to feel as close to OEM as possible, get the Excel G shocks or struts.

As I’ve outlined in other posts, I believe they are the best options for sedans.

On light trucks or SUVs with aftermarket tires, I’d always go with Gas-A-Just absorbers. Especially if you’ll be loading your car a bit more. Gas-A-Just is a more progressive shock, they regulate their damping rates by adapting to weight.

Also, keep in mind that there’s no GR2 to compare the Gas-A-Just to. All GR2s are now Excel G shocks.

This post outlines most of the main differences I usually tell people about when they inquire about these three shocks. As I said, I consider each one of these a KYB flagship, catering to a specific set of needs any car owner might have.

If you’re a vanilla vehicle enthusiast, you can check my article on how Excel G compares to OEM shocks. I’ve mentioned some more in-depth differences there, as here I mainly focused on aftermarket suspension solutions.

In case you want to venture out to other similarly priced brands, there’s always Monroe. Generally, the equivalent to KYB MonoMax is the Monroe Magnum – I’ve written about these shocks too.

Though in all fairness, I consider MonoMax to be more heavy-duty and better equipped for off-road conditions. Both can be great solutions as RV shocks on a budget too.

Anyways, if you need any additional information, don’t hesitate to shoot a comment under this post. I’ll do my best to reply.

Some general pointers to vehicles I’d recommend each shock absorber for:
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• KYB MonoMax: For HD trucks such as Chevy Silverado 1500/2500/3500; Ford F-150, F-250, or F-350 Superduty or 4×4; Dodge Ram 2500 or 3500; Toyota Tacoma or Tundra.
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• KYB Gas-A-Just: For light or mid-sized trucks such as Dodge Dakota or SUVs like Toyota 4Runner, some SUVs like Ford Bronco. These work exceptionally well for classic muscle cars such as Chevrolet El Camino, older Camaro, Monte Carlo, many 60s-80s Ford cars.
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• KYB Excel G: For SUVs ranging from Toyota RAV4 to Honda CR-V; struts for sedans or compact cars ranging from any Honda Accord, Pilot, or Fit; Lexus ES300 or ES350; Toyota Corolla, Nissan Altima etc.

Cheers!