Typical drive today, about 20 miles. Picked up some paint for the porch chairs, then Wendy's for a quick lunch, back home to put some cabinets, I got for free, in the garage. At one point I was very close to 70 mg indicated until a couple of situations beat it down some. Final reading was 67.2. I would put the improvement at close to 4-5% all other things being equal (which they never are LOL). Think I'll try Craford road tomorrow. last time I hit 110 for the length of the road. 35-45 MPH with almost no traffic, perfect for pulse and glide (EOC).

Rims and tires installed today. I bought this car May 9th 2015, 31485 on the original tires today. Could have gone further but I got the itch to see the rims on this car. Looks like MPG hit will be in the range of 5%, probably drop some as they wear in. Tires did not need to be ANY larger, clearance to the skirts under 1 inch at 50% of max turn. I have not heard any rubbing but it is close. I can feel the 6% taller final drive difference and almost 200 RPM drop at highway speeds (used to be 3k at 60 mph, now just over 2800).

Photos for above post.

55.4 mpg last tank. I can handle that now that this car handles so well with the new wheels-tires.

I'd like to run this thing on an autocross now. Refill second tank tomorrow, looks pretty good right now.

The most efficient flywheels have the greatest mass, the greatest distance from the axis of rotation. In essence the four wheels on your car are batteries. The original tires and wheels were 13 pounds each for a total of 26 pounds. The replacement wheels are just over 12 pounds, while the tires are 17 pounds each and about 1.5 inches larger in diameter. At 60 mph this reduces rpms in 5th gear by 180, down from 3000 to 2820.

You can feel the difference when accelerating. The best flywheels are those with the greatest weight at the outer perimeter. With all of the weight increase in the tread area, each wheel is a better "battery" and holds more energy that will increase coasting distances as long as rolling resistance is not too much greater than the Ensaves. As the tires "break in" I can feel the coasting distances increasing. While the tendency of this car to start rolling on the least grade was exceptional with the OE tires, the replacements are starting to show signs of the same movement.

To adjust driving technique to the new status quo, requires faster pulses, generally in one lower gear, to increase the coasting distances, utilizing the "flywheels" to their fullest extent.

Last tank (63.6mpg) was a short fill, even thought it was done at my usual station (Costco) AND at the front pump where I can drop my front wheels in the drainage depression in the pavement. Seen this happen twice, I think it is caused by another pump shutting off right when I am close to full.

Next one will show it, probably tomorrow. First 1/8th was gone at 55 miles, usually lasts 75-80 miles, probably about .3 gallon short. Even then, it would still be pushing a 60 mpg tank. Coasting distances are improving, still need to snip all the nibs off the inside of the new tires.

I averaged the last two fills together. 740.5 miles on 12.576 gallons, 58.9 MPG.
It looks like this tire and wheel combination MAY have no mileage penalty. If it does it will be minimal, maybe 1 or two MPG at most. Remember that is on brand new tires, versus the OE tires with just over the legal minimum tread depth.

Combined with the new axle, proper alignment, the 185X60 Ecopias have worked out better that I would have believed and remember, that's comparing new tires to tires on their last leg, 11/32nds tread to 3-4/32nds tread. 15x5.5 rims to 14x4.5 rims.

At certain points in turning the front wheels the outer edge of the tread is so close to the fender liners that I can't stick my finger between them. ODO under reads 6%. I have never been a fan of super low profile tires that can suffer a failure on the bad pot holes you get here.

Never heard them rub, another half inch anywhere and they would rub, just about perfect in my book. This car would be fun in an autocross now.