It depends.For our engineering minded folks here, and as a follow-up on this thread, assuming a 70/30 split (surface street/highway) usage ratio, a BB with stock tires and 3.73 gearing should, in general, yield better overall MPG than a BD with stock tires and gearing, correct? (Assuming all other variables are equal, of course)
Really appreciate those thoughts, grimm. I think I've decided to go with the BB and the 2.3/auto, so the BB tires will be bigger than the Base, so now I just need to decide whether to go with 3.73 or bump up to the optional 4.27. I'm also considering swapping the BB wheels/tires for the BD wheels/tires so 4.27 might ultimately be a better MPG/engine work levels combo than the standard 3.73 BB gearing.It depends.
Tire size factors into the equation. Different size tires need different axle ratios to be at their optimal performance target.
Having too tall (numerically lower) gears with big tires means the engine has to work harder to get the vehicle moving. It also means that you won't spend as much time in overdrive with the torque converter locked up. When in overdrive, the engine will be operating at an RPM that's below it's optimal performance range.
For the smaller standard tires on the base model Bronco, the 3.73 gears would probably net the best overall mileage. For the bigger tires, you really do want to step up to shorter (higher number) gears to match the tire size change.
Yeah, if you're going to go with bigger tires, get the higher number gears. It will save you the aggravation of finding out you don't have enough gear to run the tires.Really appreciate those thoughts, grimm. I think I've decided to go with the BB and the 2.3/auto, so the BB tires will be bigger than the Base, so now I just need to decide whether to go with 3.73 or bump up to the optional 4.27. I'm also considering swapping the BB wheels/tires for the BD wheels/tires so 4.27 might ultimately be a better MPG/engine work levels combo than the standard 3.73 BB gearing.
