The wheels on the van go round-ish and round-ish

I've noticed for a while that the rear wheels feel "lumpy", especially at low speeds-- they don't seem round. And they don't roll, I have to use a lot more fuel to get the vehicle moving and it doesn't coast, it just stops and I have to give it more throttle. I do not like any of this.

I thought maybe my wheels were out of round, but I asked a tire shop to spin them, and they're plenty round. And still the problem persisted.

I loaded down the van to haul some stuff, and noticed that the passenger's rear outer tire was bulging out the sidewall. Hmm. A vandwelling friend hipped me to the physics of tires. Apparently I'd run over enough curbs as to damage the belts of the tire, and caused a lump. I decided to spend $50 on a used tire to see if this was indeed true. And it was! New used tire (got a good deal: 65% tread), rides smooth like glass. No more lumps. The van coasts from one stop sign to another, almost from one traffic light to another, no throttle.

And I learned the secret to not running over curbs. Pull way far IN to an intersection when making right turns, until I'm practically hitting oncoming traffic. That's the only way for my rear wheels-- 17 feet behind me-- to clear any curbs. Between these two things, hopefully I can keep my tires running longer.