In an interview with CVG, Glen Schofield, general manager at Sledgehammer Games describes the Modern Warfare 3 engine as a Porsche, criticising other engines for being spaghetti like:
"Well I'll tell you one thing, I've worked on a lot of engines over my lifetime and spent a lot of time putting graphics in to them and this thing is Porsche. And what I mean by that is that it is stream-lined, everything in it is perfectly freaking clean. You can tell it's been worked on for years. It's easy to upgrade."
"We worked with engines before that are like f***ing spaghetti. You can't work on a part and put it back in without messing with everything else. Modern Warfare 3's levels now are so much bigger than the old ones because they go more vertically, they have a bigger footprint and on top of that, higher fidelity, more textures and a lot more detail."
"If you put Modern Warfare 2 next to Modern Warfare 3 you would see a huge difference. Look at all the character models, look at all the gun models, look at the reflections, look at the water. There is so much that we've added, so when someone says 'cut and paste', I don't even want to talk to them because they don't know. They just don't know. They have no idea."