I saw that you are looking to get a more fuel efficient car. Good move. Meanwhile, there are a few things you to help even an SUV’s efficiency. I find I keep forgetting to keep after the tire pressure, but when the tires are running even a little low, it makes a big difference. Change the air filter more often than you have to..that helps, too. Keep the speed down on the highway, at least most of the time. A Yukon is as aerodynamic as a rolling brick, so it makes a big difference. If you look around and decide that you want to keep your Denali, after all, (I would have a hard time giving one up) look into investing in exhaust headers. Not to go fast, but because they generally improve mileage. Results vary, depending on how free flowing your stock design is, but I seem to remember that an extra 10% was not uncommon, and it all adds up. Since our vehicles all contribute to pollution in the most direct way, it makes sense that whatever we can with them would make the biggest impact.

I read that tip on one of the many “green” websites I’ve been looking at & I’m keeping an eye on it (it’s nice because the tire pressures can be displayed on the dashboard)

I’m also looking into getting a Hybrid Rolling Brick