Another car: 96 Civic EX Manual 42MPG HWY.
 

Well I bought another car a 96 Honda Civic EX Manual with 200k on the clock. Everything stock just overinflated tires. I travel 30 miles each way to work with A/C OFF I have been getting over 40MPG at 60-63MPH about 5% of the drive is city so for the whole trip I get over 40MPG. I want to see the best I can get with A/C OFF then see what I can get with A/C ON. I think it makes a big difference on these small 1.6L motors maybe 5MPG if I had to guesstimate now. Right now I have stock rims and tires on it as soon as I get my highest MPG for the trip to or from home I am going to put my larger rims and tires on to see if it affects the MPG negatively.

The a/c does make a huge difference with these things. You could try pulsing it, as it blows cold for a bit after it's off you can get away with it rather comfortably, though that is annoying as hell.

I doubt the heavy rims will affect you much since you're not doing much acceleration, the larger tires might though!

I pulse my AC when I absolutely have to use it.

I just turn it on when I'm going downhill and turn it off when I go uphill. That way I can stay cool and not tax my FE too much.

On level surfaces I blast it until I'm cold, then turn it off until I'm too hot, then blast it, turn it off etc.

It's more efficient to blast it then turn it off than to leave the AC on 1 or 2 the whole time.

I am in Florida, the A/C can barely keep up when its always on, might need some tint. As soon as you turn off the A/C the vents blow warm to hot.

My rims and tires are not that much bigger. Current are the stock 14" steelies and my other rims are 15" and but wider and taller than stock.

if high pressure in the tires is the only mod, that civic is running in great condition.