Hi Scotty,
I love my Mitsubishi 3000GT VR4, but I also love the Earth. Is there a catalytic converter that I can buy that cleans the exhaust better but does not need to restrict the exhaust pressure to work?
Bonus Question, I used to have an old 1978 Toyota Landcruiser FJ40 with a 4.2 L i6 engine. I had a custom manual transmission with a 5th gear for fuel efficiency. When I would drive on the Highway, I would take it up to speed and pop it into 5th gear, and have it running at 60 mpg at only 1200 rpm. It saved tons of gas.
If I got a vehicle with eight cylinders, could I adjust the engine to run at 60 mpg at idle rpms? That would really save a ton on gas...
I really love your show, and thanks.
Sincerely,
Daniel Slack
Lincolnville, ME
"Maine, what America is supposed to be."
Your Mitsubishi stock catalytic converter should be just fine as long as it's not plugged up. The earth won't notice if you install a different one. Of course there are high-flow cats available if what you're looking for is more performance.
It is extremely unlikely you're going to be able to get 60 mpg out of an 8-cylinder engine. If it was as simple as you suggest the car manufacturers would already be doing it since their back is up against the wall to eke out as much mileage as possible. The most efficient rpm range varies depending on the engine but is typically higher than idle speed. (My 8-cylinder vehicles get around 12-14 mpg and I'm fine with that.)
