Just back from a 1000 mile trip, so I actually had the chance to
see what kind of mileage I can get from the -6. Normally with
short trips and lots of autocross I never can check it.

1026.8 miles, which is really probably as low as 950 due to
the 205/55 tires and info from mapquest.

no more than 36.7 gallons (at the end I filled up right to the brim).

950/36.7 = 25.9 mpg

That's not bad with the 75mph highway speeds and having
6 carbs with the 55 idle jets and 30 venturis and low profile
tires.

2.0 motor?

tell me about your wheels/tires. Do 205/55 give a punishing ride, or noisy on the frwy? Are they too bumpy for a street car? Do you have them on 6" wheels?

Mark,
I found a tire calculator sizing thing on the net.

Your 205/55-15 tires are -1.14% difference in diameter from the stock 155/75-15 that are shown as stock pre-75 cars...not sure about the six.

So I would say 998.6 miles (i fi did that right)
27.2 MPG...

Cool...

Rich

Yep, all original 2.0-6 motor including exhaust. Only carb
changes, which I'm told are really for adjusting to today's
gas and eliminate artificial restriction based on emission
laws.

Original tires would be 165R15 which are roughly 78
aspect ratio. I have original spare so I could compare
diameters.

But the numbers written on the sidewalls are really only
approximate.

I don't think the 205/55 tires are very stiff, and they are
on 5.5 fuchs. But then I'm comparing them to the
autocross kumhos which ARE very stiff. I have 180 rear
springs and 21mm front bars so the car is pretty stiff
over bumps.

My 205/55 tires are Bridgestone RE730, which are very
noisy. Other tires are not so much.