[oil pan 4]

If you want more power in general or for towing, a good tow machine and better fuel economy starting off with a gas engine is the wrong way to go about it.

With a gas engine your mods are going to be fighting each other, most of your go fast mods will be trying to move more air through the engine and there for you will burn fuel, going against any eco engine mods.

The worst thing about a gas engine is the otto cycle its self, there is nothing you can do to fight isobaric expansion that starts off the cycle. The is the main process responsible for limiting power and fuel economy on a gas engine.

This is why we like diesels. Big intakes are good, bigger air fiters are better, ram air is great. Even bigger turbo chargers can help both power and FE. On the exhaust side big free flowing straight pipes do offer improvement in all driving conditions.
Why, because on a diesel you replace the pesky isobaric expansion that is all but impossible to work around. With diesels we have isentropic compression and isentropic expansion, that means the more air you can start off the cycle the more efficient and powerful it will be. On a diesel your isentropic expansion can be filled with air or burned fuel. So more air is better.