Chevy Silverado 1500 – Silverado Gas Mileage – Repair History – Silverado Accessories – Buying A Chevy – About Us
Our stock Chevy Silverado came with the 3.08 gearing common to most half ton trucks today. We would have liked to have the optional gearing but the only vehicle with the options we most desired available was not so equipped. No problem, a trip to Dave's Automotive in Cheney WA and this situation was quickly remedied.
The question was then, which gear ratio best suited our driving styles? Both 4.11's and 4.56's are great off road truck gears but with our desired limit of 33" tires and a need to limit the entry height into the cab and bed made the related tire size and lifts inappropriate for this truck. We were looking for something a bit less aggressive and something better suited for a daily driver as this Chevy is going to see lots of miles over the coming years.
While both 4.11's and 4.56's are great off road gear choices, our desire for a daily driver with just a mild lift limited us to the 3.42, 3.54, 3.73, or 3.90 gears for a compromise in both mileage and towing capabilities. Changing from 3.08 gears to 3.73 gears is not going to adversely affect the driving of this truck at highway speeds. SEE: Installing 4.56 or 4.11 gears in a Chevy Silverado 1500.
We opted for the 3.73's as the best choice for our driving habits when combined to the other changes we will be performing. The 3.73's combined with the 33" Coopers will result in a freeway rpm of around 1850, well into the new power band and torque curve. Drivability should be very good with this combination and the mileage should not take a serious hit either.
Installation was performed by our local mechanics where the change was quick and flawless. Not all shops have mechanics experienced in gear changes so be sure to do some research before you make this choice. Dave's Auto performed the gear swap on our other Silverado when he installed a set of 4.56's along with a modified 383 CID engine. That truck performs great and is more of the off road vehicle than a daily driver.
All the paperwork means nothing if the end results are not performing as intended. Here we look at out Chevy Silverado and see how the gear swap affected the performance and mileage of our long term daily driver.
First off lets talk about the performance gains from these modifications. Swapping to 3.73's from the stock 3.08's has livened up the throttle far more then we had expected. This swap came after the Borla Cat Back Exhaust and Airaid Cold Air Intake and seemed to really bring out the best of these prior mod's too.
When correcting the speed calibration we never bothered to change the stock shift points but may try this in the near future. As it is, the 3.73 gear swap seemed to make the shifts quicker and noticeably more solid. As it is we are pretty happy with the overall setup and haven't had the desire to experiment with the shift points yet.
Mileage figures improved as expected especially when we kept a lighter foot on the throttles. Speed is still the common factor in getting the best mileage out of your vehicles. The 2011 Chevy Silverado is no exception to this and our best mileages seem to come around the magical 50 mile per hour figures. Even up into the low 60's the mileage numbers noted a fair improvement. Get much above the 65 mark and mileage begins to drop off.
Any time we start getting 20 miles per gallon out of a full size pickup we really start to smile. And getting this loaded down on a trip over the Alaska Highway, up and over the Continental Divide and on some rather ridiculous or should I say precarious road conditions is totally amazing.
All said and done, the gear swap was a total success as gas mileage is still quite excellent and the power difference is great. Towing and hauling are much easier and the truck is under less strain when the situation calls for putting to work the extra ponies from all the other mod's.