A TB spacer works better as a paper weight and WAI sounds like a bad idea. I would try some fuel system cleaner. I have always thought that it was a scam untill I actually tried it. Maybe it was just a coincidence but I used it about every other fill up for a month and i went from 10.5 MPG to 12 MPG in my 07 Tundra. I would also make sure that your mass air flow sensor is clean.

 

I get like 8-10... Maybe 12 or so on the highway. I tries the "baby the throttle" method. Not fun to drive like a grandpa and have shitty cars blow their horn at you and flick you off.

But on topic, doesn't more power mean less work for the engine to operate at higher efficiency or is that what we tell ourselves to justify going fast?

 

Read an interesting article yesterday actually about fuel economy....

It appears that through all our advances in technology, when it comes to new engines, fuels, oils ...etc etc....the early 80's when fuel injection was introduced was the point where everything got its biggest increase in fuel economy and actually attained the best economy.

A 1980, the Honda Civic gets 33 MPG...A 2011...it gets 30 MPG

Nissan Sentra...1982 36MPG....2011, 29MPG

Back than, the primitive form of testing they had for MPG though...those cars only got in the 20's....using one of those cars today on modern economy testing equipment...its a different story.

I have a buddy with a 68 Karmen Ghia...he averages 32MPG, on a 1.6L carbed 51hp engine and 4 speed trans.

Its not the vehicles that got more efficient from the looks of things...its the testing that has gotten massaged to reflect larger numbers.

 

I'm sorry, but no.

You have to realize that the 1980 Civic that got 33mpg weighed just over 2000lbs, and had under 60hp. The 2011 Civic that gets 30mpg has almost three times the horsepower and weighs over 500 lbs. more.

If you're trying to say that engines haven't become more efficient, you're just flat out wrong.

 

Not engines...vehicles

Engines are definitely more efficient...but you now need 3 times the horse power to move the vehicles around. so fuel efficiency suffers.

but you would think that 3 times the power but only an increase in weight of 25% the MPG would have increased....and by much more than it has.

I have even driven my share of 80's pickups with 305's that got 18-20 MPG. They couldn't get out of they're own way they were such dogs...but you could still haul a load or a decant size trailer with them.

 

I would say your biggest improvement would be from a tune with lean cruise enabled.

 

the guys who have done the 6-speed t56 swap seem to get pretty decent highway mileage.