TEIN Coilovers: Basis Z vs Street Advance Z vs Flex Z – Comparison Guide

TEIN Coilovers have gone through changes over the past few years, with TEIN redesigning their full line of coilovers to be more competitive in price and features yet retain the quality and performance that TEIN has been known for.

TEIN had three main coilover lines that they sold, each at a different price point and each with different features, specs and intended use. These were the TEIN Basic Coilovers, TEIN Street Advance Coilovers and TEIN Street Flex. In order to be competitive with competitors releasing coilovers that were at a lower price point, TEIN knew they had to move production from Japan to other countries such as China. TEIN not only moved production out of the country but they also redesigned the shock to be a sealed unit rather than a rebuildable unit. This made it so if the shock was worn, it would need to be replaced rather than repaired. For the most part, this isn’t a big concern, because for the cost to rebuild a shock, you could just replace it with a new one, and that’s the route TEIN took. Their newly revised pillar coilovers were slightly renamed to TEIN Basis Z Coilovers, TEIN Street Advance Z Coilovers, and the still built in Japan TEIN Street Flex Z Coilovers. Below, I’ll go into the differences between each one so you can decide which is right for you.

TEIN Basis Z Coilovers

TEIN Basis Z Coilovers are TEIN’s entry level coilover. Coming at the lowest price point makes this the most popular coilover, but it’s also the one with the least amount of features. Designed to be used by those who are more after a suspension that has new shocks and adjustable height springs but don’t need camber adjustment or damper adjustment. These require that you reuse your OEM top hats. TEIN includes 4 pre-adjusted twin tube shocks that are designed to take the abuse of a lowered vehicle and offer enough shock travel to give you a good price and longer range of performance for the shock. This means that typically this setup would ride more comfortable than a car with OEM shocks and lowering springs. Given that (depending on the application) you can adjust the coilovers from about 0″ of drop to about 5″ max drop, you can really set the car to your liking.

TEIN Street Advance Z Coilovers

The TEIN Street Advance Z Coilovers one up the Basis Z by giving you 16 way adjustable shocks. Still not including top mounts, these coilovers allow you to fine tune the suspension from soft to firm and anywhere in between.

This line also allows the use of an EDFC system which gives you the ability to adjust the damping from the cockpit and not manually. The TEIN EDFC system really comes in handy to make on the fly adjustments and feel the changes real time to really dial in the suspension to your preference.

TEIN Street Flex Z Coilovers

As their most popular top-of-the-line coilover, the TEIN Flex Z Coilovers are still made in Yokohama Japan and are a true JDM coilover system packed with all of TEIN’s technology. This system incorporates the 16 way adjustable twin tube shocks and includes TEIN top mounts. TEIN pre-assembles these (though check pre-load before installing), so these are easier to install since you don’t have to disassemble your factory shock and spring to remove the top mount. Many applications, depending on suspension design, also include front camber plates to give you a full race suspension with plenty of adjustability for anything from the occasional weekend track enthusiast to competition use.

So which TEIN Coilovers are right for you?

Once you decide which coilovers you prefer, check out the Redline360 Store for all of the available applications. Our site has the spring rate and height adjustment range for each part number to help you decide which is right for you. If you’re still not sure, you can ask for recommendations below in the comments. Be sure to state the year, make and model of your vehicle plus the kind of driving you do.

If we missed anything, please comment below!

2 comments
    1. Hey Joni!

      The Tein “Z” line is all non rebuildable. The old non “Z” line used to be. However, the Flex Z is the only one that’s made in Japan out of the Basis Z and Street Advance Z.

      Also, a replacement shock is around the same cost as rebuilding (maybe a bit more), so it made more sense to just have customers replace a worn shock instead of getting it rebuilt.

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