Monotube vs Twintube
Anyone who is buying coilovers for their Subaru should watch the following two videos. One of them is less than a minute long, and the other is just over two minutes long. These three minutes and change will be more beneficial than hours of Facebook group research. There are a lot of factors to consider when purchasing shocks, but one fundamental, critical thing to understand is the difference between twintube and monotube shocks.
The only real advantage with twintubes is the fact that they’re cheap to manufacture. Monotubes will outperform twintubes in pretty much every measurable way. Monotubes do not suffer from cavitation the way that twintubes do which means that monotubes are far more consistent. This gives you both better performance and a better ride quality. The piston diameter is much greater which makes the usable piston surface area almost three times the size in many cases. Greater piston surface area means more damping adjustment, and it also means that the engineers designing the shock are able to make it far more digressive which again means both better ride quality and better performance. Because a monotube shock piston directly touches the outer wall of the shock body monotubes shed heat a lot better which is a critical part of a shock absorber’s main job (converting kinetic energy into thermal energy). They also have significantly more oil capacity. Shock oil only gets changed every 30k-70k miles, so greater capacity really helps with things like shearing and viscosity index over time.
Recently I have seen a lot of people going with twintube options that are overpriced, don’t last as long, don’t perform as well, ride worse and have significantly less rebound adjustment when they could be buying something high quality and monotube for the same money. If you are planning on purchasing coilovers for your Subaru spend a couple of minutes and watch these videos. We offer everything from the best value for the dollar monotube coilover set for these cars to the absolute highest end monotube coilovers money can buy. Not many vendors or manufacturers are willing to have public technical discussions on shocks anymore which is a shame. We have built our reputation on getting customers better results for less money when it comes to suspension. Adamantly recommending monotube shocks over twintube shocks for the past 13 years is one of the ways that we have been able to do this.
KYB’s video:
If you guys have any questions about monotube vs. twintube or anything related to coilovers or suspension mods I’ll be glad to help here if you reply to this post, or you are also always welcome to contact me directly. 
Thanks,
Geoff