My 2021 Toyota Tacoma Was Getting 20-22 MPG, But When I Lifted It I Get 15 MPG at 65 MPH And It's Consistently Downshifting Now
When you modify a car or a truck, sometimes things go wrong. And that’s exactly what happened to Tim Bowman on the 2016 Thru 2023 Toyota Tacoma Owners Facebook Group, when they decided to modify their 2021 Tacoma TRD.
The owner of the truck, Bowman, took to the group to explain what happened and to get some advice about what to do next,
Ok, I was happy about my Double cab 4WD 21 TRD Sports gas mileage and was getting 20-22 all day and super happy with the performance with the OTT tune, until I lifted it just 2" front 1" rear and new 265-70-17 Falken wildpeak AT4. Now I'm blessed to get 15/16 MPGS at 65/70 mph. It's consistently going from 6th to 5th and if I use cruise control it'll downshift to 4th on a slight incline. I understand wind and temperature is affecting this but it feels worse than stock now, but it looks nice… anyone dealing with this too? I mean it's not the biggest deal but it just kinda sucks on the highway now.
Some users took to the comments to remind themselves why they kept their vehicles stock, “That's why I keep stock height and tires. I know what it does to fuel consumption.”
- When Toyota first introduced trucks like the 1964 Stout to America, buyers dismissed them as underpowered oddities. U.S. drivers were loyal to brawny domestic pickups, viewing compact Japanese trucks as unserious for work or recreation.
- The 1964 "Chicken Tax" slapped a 25% tariff on imported light trucks, making Toyotas pricier than homegrown rivals. This forced Toyota to get creative, eventually building U.S. factories in the ‘80s to sidestep the tax and gain a foothold.
- Toyota’s trucks have carved a legacy in brutal off-road racing, with the Tacoma and Tundra proving their worth in events like the Baja 1000.
How It Affects The Tacoma
Lifts and larger tires might make a Tacoma look ready to conquer Moab, but they sabotage its carefully calibrated aerodynamics and powertrain harmony. Raising the body increases wind resistance and at highway speeds, air doesn’t glide smoothly over the truck; it slams into the front end, swirls chaotically underneath, and drags against the raised suspension. Combine that with heavier, knobbier tires, and the engine suddenly faces a relentless enemy, rolling resistance.
Those rugged Falkens grip dirt like Velcro, but on pavement, their aggressive treads flex and squirm, forcing the engine to burn extra fuel just to keep them spinning. It’s a double whammy, your Tacoma is now fighting both the air and itself.
One user even commented, “Your new tires are heavier, makes gas mileage worse ofc. I had the same setup but I was on rugged terrain Goodyears and I could feel how heavy the tires were in my clutch”
Then there’s the transmission’s rebellion. Modern trucks like the Tacoma rely on precise gear ratios and shift patterns to balance power and efficiency. Larger tires effectively “regear” the truck, altering how hard the engine works to turn the wheels. The Tacoma’s computer, programmed for stock tire size, doesn’t recognize the change. It still thinks the truck is running smaller tires, so when cruising at 70 mph, the engine lugs at lower RPMs, prompting frantic downshifts to avoid strain.
The result? A transmission that dances between 4th, 5th, and 6th gear, guzzling fuel like a ’70s muscle car. The owner’s OTT tune, a popular performance upgrade, might have sharpened throttle response initially, but it’s now working against the truck’s new reality, amplifying the inefficiencies.
What Happens Next?
In the end, it’s a cascade of unintended consequences—each modification stacking like dominoes until the whole system teeters. The lift, the tires, the tune—they’re all conspiring against him. That sleek, aggressive stance comes at the cost of aerodynamics, turning his Tacoma into a rolling brick wall at highway speeds. The chunkier tires claw at the pavement, sapping power and forcing the engine to chug harder, while the transmission, confused by the new tire size and altered gearing, frantically hunts for the right gear like a lost hiker.
Even the OTT tune, designed to sharpen throttle response, now amplifies the chaos, demanding more fuel to compensate for the truck’s newfound clumsiness. What began as a quest for style and capability has devolved into a mechanical tug-of-war, where every tweak, no matter how small, pulls the truck further from the precision of its factory engineering. The lesson? Mods might transform your ride’s attitude, but everything comes at a cost.
Image source and credit: By Tim Bowman from his post on the 2016 Thru 2023 Toyota Tacoma Owners Facebook Group.
Noah Washington is an automotive journalist based in Atlanta, Georgia. He enjoys covering the latest news in the automotive industry and conducting reviews on the latest cars. He has been in the automotive industry since 15 years old and has been featured in prominent automotive news sites. You can reach him on X and LinkedIn for tips and to follow his automotive coverage.