unless you're fighting for that last watt of savings, for the most part tire width won't make a difference, and not nearly as much as tire choice (compound, tread design, stiffness, weight, etc.)
I went from the stock (Bontrager 700x28) tires to 700x35 SCHWALBE ENERGIZER + TOUR WIRE tires and I picked up 2mph average speed on flats easily. Note those are actually e-bike rated tires as well, so they're wearing like iron (over 2800 miles now) and they have amazing grip.
there have been tons of studies on tire pressures versus resistance (watts) that have shown pressures within the tire's recommended range have very little effect on resistance, unless you're basically a TdF level cyclist. We run the wife's tires 30psi off the rated max, simply because it all but eliminates her getting puncture flats (she's a larger gal, and already has semi balloon tires installed), and her newer tires (Michelin Country Rock 26 x 1.75") also netted her an increase in speed simply because they were lighter and had a less aggressive off-road pattern.
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2007 Jeep Liberty Sport 4x4 3.7L 6spd
- MOABs with Goodyear Wrangler All-Terrain Adventure With Kevlar 245/70R16
- JBA UCA 4.5
- OME 790/948/90009/N32
- Western Suburbanite 7'4" plow
- DetoursUSA Backbone
- HF 12k# winch
[SIZE="1"]WTB: project liberty near N.NJ. stick shift, 4x4, working motor optional,
CHEAP[/SIZE]