If you want to address fuel consumption, you need to measure miles driven and gallons bought when you fill the tank.

Zero the trip odometer every time you buy gas.
Next time you fill up, you have your actual miles available.
You can't judge properly if you judge by "tankful" when you decide to fill up.

I think I may have just gotten some improvement in my 245 (non-turbo, auto trans) by taking care of a couple bad vacuum hoses. It's a good thing to check.

The hose to manifold from Flame Trap was a problem. It seems to be metric, and a tough size to find. We had 2 cars out of 3 with a slightly-too-large US size hose there, apparently leaking vacuum.

Same goes for the little curved one from manifold to the thin hard plastic tube.

Of course they all need replacing now and then.