CA18DET vs SR20DET: Which Is Better?

While the CA18DET does have a few advantages over the SR20DET, Nissan enthusiasts generally seem to prefer the SR20DET for its performance and accessibility.

CA18DET Overview

The CA18DET is the older engine of the two and was first used in cars like the Silvia S12 and the 180SX in the late ’80s. The North American versions of these cars didn’t get the CA18DET; instead, cars we’re familiar with, like the 240SX, came with the KA24DE.

The engine code is pretty descriptive and tells you a lot about it if you know what it stands for: CA is the name of the engine family it belongs to. 18 refers to the displacement (1.8 liters), “D” stands for dual overhead cams, “E” stands for electronic fuel injection, and “T” stands for turbocharged.

The CA18DET was the last engine in the CA family to be made as well as the most powerful version, putting out 166 horsepower and 168 lb-ft of torque in stock tune. It was discontinued in 1991 because its cast-iron design made it too expensive to produce.

If you’re planning on upgrading your CA18DET, you can get a decent amount of power out of the stock internals with a better turbocharger and other supporting upgrades. You can achieve a lot more power if you opt for forged internals (some report making over 700 horsepower with built internals), but be prepared to spend a lot of money in that case. 

SR20DET Overview

The SR20DET was developed with the intent of replacing the CA18DET and was first used in the Nissan Bluebird in 1989 (although that car was only sold in Japan). The SR20DET was never sold in any cars in North America either.

As the name of the engine implies, the SR20DET is the larger engine of the two, displacing 2.0 liters. The other major difference between the SR20DET and the CA18DET is that the SR20DET uses an aluminum block instead of cast iron, and the SR20DET uses camshafts and rocker arms to actuate the valves, instead of just a camshaft.

The SR20DET produced more power than the CA18DET due to its newer, larger displacement engine; depending on the car it was installed in, it produced anywhere from 201 to 247 horsepower from the factory.Many owners report making 400 horsepower or more from their SR20DETs with stock internals and a few upgrades.

If you’ve got the money to spare, you can get some serious power figures out of the SR20DET. Fully built and stroked SR20DETs can produce over 1,000 horsepower, but you’ll have to take the engine a long way from stock to get there.

Comparing the Two

We’ve gone over the basics of these engines, but the question is, which one of them is better? We’ve already mentioned that the Nissan community seems to prefer the SR20DET, but what justifies that preference? Let’s compare some of the main differences between the two and see how they stack up.

The main difference is the increased power that the SR20DET offers. It makes more power than the CA18DET in both stock form and when it has been heavily upgraded. The larger displacement of the SR20DET means that it also makes more low-end torque than the CA18DET.

The main advantage that the CA18DET has going for it is its ability to rev higher, owing to its smaller displacement and its more direct valvetrain. While the SR20DET uses a DOHC + rocker arm setup to actuate the intake and exhaust valves, the CA18DET has its camshafts actuating the valves directly.

However, the main reason so many people go for the SR20DET when doing an engine swap is the availability of aftermarket parts. When compared to the CA18DET, there are way more compatible aftermarket parts available for the SR20DET, which ultimately makes it easier for people to modify their cars the way they want. 

In terms of reliability, both engines are known to be pretty reliable, at least in stock tune. However, due to the wider availability of aftermarket parts for it, it’ll likely be easier to modify the SR20DET and ensure that it remains reliable. 


If you’re trying to decide between swapping a CA18DET or an SR20DET into your project car, the consensus is that you’re better off with the SR20DET. And really, the facts make a pretty compelling argument; the SR20DET makes more power from the factory, it’s a more modern engine in general, and it features much more comprehensive aftermarket support.

That being said, the CA18DET still has a few advantages going for it, such as the simplicity of its valvetrain setup and its ability to rev pretty high. While on paper, the SR20DET is overall probably the better engine, the CA18DET still has its share of supporters, and it still has a decent amount of tuning potential.