I'm getting a bit tired of driving at 58 mph That's how I spec'ed the truck myself and my CAT does 1300 RPM at that speed; or 1350 RPM at 59 mph. I have 295 low pro tires and 3.73 rears with a 13 speed Eaton. I want to basically shorten my work day a little bit and I can either switch to 24" tires or change my rear axle ratio to something like 3.55 or 3.30.
I figure with 3.30 ratio and current lo-pro tires the engine will turn at the perfect 1,315 RPM at 65 MPH
BUT
at 60 MPH it'll turn only at 1,214. No way I'd be able to pull any sizable kind of a load at that RPM in the top gear.
So, my question is this: if your truck has a very fast ratio like the 3.30 I'm using in this example, how do you manage to drive thru areas with 55 or even 60 MPH speed limits?
I'm pretty sure my fuel mileage will be in the toilet if I drive thru Michigan at 60 MPH in Gear 12 (8 low) instead of Gear 13 (8 high)...
Any comments will be appreiciated.
PS: I'm based out of Ontario, Canada and often drive through PA, NY, OH, MI, IN, IL.