I’ve always been a fan of Miatas. They’re small, nimble, and the most fun you can have at and under the speed limit. So when I was given the opportunity to drive a Miata with a different engine, I jumped on the opportunity. And boy am I glad I did.
The engine that’s has been transplanted under the hood of this Miata is a 2.4L Ecotec four cylinder. The Ecotec is an all-aluminum engine from GM, with dual overhead cams and variable valve timing. This specific Ecotec is called a LE5, and is found in the Pontiac G6 or Saturn Sky. On the surface, it might be hard to understand why someone would want to stuff a mid 2000s GM engine that was meant to be in economy cars, into a Mazda from the 90’s. But let’s look at it on paper.
The Miata I drove was an M edition, meaning it originally came with the 1.8L inline four cylinder from the factory. That means it had about 133hp at the crank when new. The 2.4L put out 170hp from the factory, and if you put an intake and exhaust on it, 200hp is well within reach. Paired with the extra horsepower, is a wider power band. The LE5 starts making power at 2,000 rpm, and doesn’t stop until a little before 7,000. That means more torque at your disposal at any given time.
So is it worth it? Putting a whole new engine into a car for less power gains than a decent turbo? Yes. First of all the swap is pretty easy. All you need is new engine mounts, and oil pan, and an adaptor plate if you want to use the stock Miata transmission (This car did). In the world of engine swaps that’s a walk in the park. The 2.4L also does something that turbos can’t: Keep the signature Miata feel. Boosted Miatas are faster, but they no longer have that charm of a stock Miata. The fact that the LE5 is naturally aspirated, helps the Miata feel like itself, only better.