Coilovers: True Rear vs OEM Style – What’s the difference? Which is better?

When selecting suspension upgrades such as coilovers for your car, you’re presented with a lot of options. Once you narrow down what brand you want and go to order it, you might be presented with another choice that you didn’t even realized you had to make – true rear vs OEM style. Many people see the word “true” and assume that it’s better than just OEM style and don’t completely understand exactly what the differences are and which is right for them. Since we get this question so often, we decided to put together an article that describes the two different styles, which is better, what are the benefits, and what is right for you.

So first lets get into the definition of these two different styles of coilovers. True Rear Coilovers are coilovers where the spring is over the shock. This is the classic definition as coil-overs are coils OVER shocks, which is why they’re called coilovers. In OEM Style Coilovers, some cars from the factory come with the shock and the springs divorced, or separated. See below for an example of what the two look like:

In the two examples above, you can see that the true rear coilovers have 4 complete assembled coilovers, and the rears look like the fronts. The spring sits over the shock. In the example under that, you can see that the two shocks on the right do not have springs over them, he springs are separate and have two adjustable collars that go above the spring in a spring bucket. Since they’re separate, they’re OEM Style or Divorced, vs the True Rear above. If you have OEM style, you can get an aftermarket setup to allow you to get a true rear conversion.

Benefits of True Rear Coilovers vs OEM Style

Ok, so now that we established the difference of True Rear vs OEM Style Coilovers, which one is better?

If you look at pure track cars, or cars that are purpose built to go around a race track as fast as possible, nearly every time they have a true rear setup. Now, keep in mind, these cars are driven generally by professional or hardcore track racers and not on the street. Does this make them better? It’s tough to say as race teams specifically dial in their cars to squeeze out every bit of performance out of them. But if you look at this factor alone, yes, the true rear setup would be superior in a track setting.

For the daily driver, you won’t notice any performance difference either way. You would need to push your car pretty hard, and be going after every last second on the track to get the true benefits from a true rear coilover. One negative of true rear is that on cars such as the 350Z and G35, you would need to replace your rear spring bucket with a delete arm, which adds to the cost. Here’s an example of such an arm: Godspeed Toe Arms 350Z / 370Z / G35 / G37 Rear Bucket Delete AK-190. However, the benefit of replacing the rear spring bucket is you save a lot of weight as those OEM pieces are very heavy (even if made from aluminum).

Some customers state they have better ride quality with true rear vs OEM style. Keep in mind, the variances here can also be due to different spring rate and shock valving.

Do I need any re-enforcements?

If you go with a true rear coilover setup, you will likely, depending on what car you drive, need to have some kind of strut tower reinforcement as the added stress can crack the strut towers. Cars such as E46 M3s and E90/E92 M3s have OEM divorced setups, and it’s rare for them to convert to a true rear style, but when they do, they either have a full roll cage to support the strut towers or some other kind of bracing. Many other cars such as a 350Z or G35 generally do not need to add the extra stress supports. Check with a local shop to determine if your vehicle is one that requires support to help determine if it’s worth it to you.

For what it’s worth, many coilover brands have stiffer springs for OEM style and softer springs for true rear style. And normally they do not go softer in just the rear for true style, they also go softer in the front to ensure you have proper balance. You can go softer on true rear setups because you will have higher roll stiffness for your spring rates and lower weight overall.

Which one goes lower?

If you’re just after looks and want that super low stance, you can generally max out your car with either true rear or OEM style. However, if you’re looking for maximum low, we would recommend you go with air suspension instead of a static coilover, regardless of rear style.

Are all cars divorced from the factory?

No. Some cars already are true rear from the factory. For example, a 1992 Honda Civic DX has an OEM true rear setup while a 2020 BMW M2 Competition has an OEM divorced setup.

What setup do you have?

We’ve love to hear feedback from you. What setup do you prefer? If you had to pick true rear vs OEM style, which would you pick? Leave your comments below!

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