Affect of wheel on acceleration

My colleague and I are having a discussion (ie argument) which we hope members of this board will settle for us.
Following a statement I made that "Smaller wheels on a car result in better acceleration" my colleague stated that this would be primarily due to the smaller wheels being lighter, with the size being a marginal factor.
My position is that the weight is a marginal factor and that even if the smaller wheels (assuming a wheel to include the tire) weighted *exactly* the same as the original larger wheel, acceleration would still be improved. We are also assuming in this case that wind resistance is not a contributing factor...so lets assume the cars are driving in a vacuum (and yes, I know a conventional car won`t run at all in an vacuum...).
So, (where "smaller wheel" means "smaller diameter"; q) Smaller wheels = better acceleration primarily because of the size.
True or False? (no mechanical explanation required - we know the physics...just looking for real world)

The smaller wheels will probably give you less grip which goes against your effective gear reduction -- so its not a simple question.

and small wheel, that both wheels are the same weight, that the tires have equal traction, etc., etc., the smaller will have better acceleration. Why? Because accelerating a mass at smaller radius is easier. However, the difference would IMO be so slight as to not matter in the least. Not even measureable outside a laboratory.

accelleration than larger wheels, because they will effectively lower the gear ratio.

not depend on wheel size, and is the same. What you will observe, though, is that smaller wheels are easier to spin, because the force (and the acceleration) is greater, and can more easily exceed the grip.

Tires do not follow the simplistic friction law from your high school physics book. If you get more ruber area on the road you get more traction. Granted if you are talking about a small change it will be less significant than changing brand of tire, but if you do something extreme this will be important.

same tread width.

coefficient of the material remains the same, THEN the traction force remains the same. The traction force is equal to (traction coefficient) times (pressure) times (area). However, since (pressure) times (area) equals weight, this product remains constant for the same car (same weight). Therefore, if the traction coefficient doesn`t change, the traction force won`t change, as long as the car weight and the rubber/asphalt interaction (tyre type) don`t change. What this means in practical terms is, that the same car, stopped, with locked wheels, should need the same force to start sliding along when being pushed, regardless of what size tyres (and their inflation pressure) it has on. Conversely, when accelerating, the smaller tyres will more easily reach the traction threshold and spin, since they develop a greater force. With infinitely sticky tyres and a given torque, a car with smaller wheels will accelerate better. In reality it all depends. I`m curious how much real world behavior differs from this idealistic one.

launch. Comparing any normal cars for rolling acceleration will not encounter traction limited acceleration, and thus will see an increase in speed with a decrease in tire size.
Also, I assume you are thinking of the big tires on the dragsters. They are already geared to use them. A "regular" car will generally see a decrease with tires that large, and an increase with smaller diameter tires.

enough to contain enough reinforcing material to resist shear, and (b) its spin rate is below its rated limit.
A jet dragster is often equipped with much smaller rear tires -- there is no need for the additional reinforcing material because all the wheel does is spin -- it may lag (drag) behind as it skips along the surface; that is, if the rear wheels are larger than the competitors`, all things being equal, the race will be lost.
For wheels that have torque, the smaller a diameter the tire, the faster acceleration will be achieved at the expense of top-end speed and efficiency; the larger the tire, the better the top-end performance. Using quarter-mile times as a reference, one will experience diminishing returns as the tire size shrinks along with the top-end speed.