Secondary Air Injection Pump Failure
high- Typically appears
- 70–100k mi
- Estimated repair
- $1,100 – $1,800
2021 Toyota
Tundra Double CabPickup
5.7L V8 · Pickup
The 2021 Toyota Tundra Double Cab is the final model year of the first-generation Tundra's long-running platform before Toyota's complete redesign arrived for 2022. It carries the legendary 5.7L V8 — one of the most proven truck engines ever built — paired with a 6-speed automatic. While the platform was aging by 2021 (infotainment and fuel economy lag behind rivals), the powertrain's durability record is exceptional. Owners regularly push past 200,000 miles with straightforward maintenance. The Double Cab body gives you a full-size rear seat that's genuinely usable for adults, an 8-foot bed option, and a towing rating of up to 10,400 lbs. It's a working truck first — not the most refined ride on the highway, but it more than earns its keep when you actually put it to work. For Lake Geneva-area owners, the main caution is the salt belt: Wisconsin roads are hard on underbodies, and the Tundra's frame and exhaust components need proactive attention each fall and spring. Budget for annual undercoating and keep up with those fluid changes, and this truck will reward you with a decade-plus of low-drama ownership.
Reliability
4/5
Verified data
Engine
[object Object]
Drivetrain
4WD
Fuel
Gasoline
MPG
13 city / 17 hwy / 15 combined
Seats
5
Doors
4
Body
Pickup
MSRP
$42,025
Overview
AI-curatedThe 2021 Toyota Tundra Double Cab is the final model year of the first-generation Tundra's long-running platform before Toyota's complete redesign arrived for 2022. It carries the legendary 5.7L V8 — one of the most proven truck engines ever built — paired with a 6-speed automatic. While the platform was aging by 2021 (infotainment and fuel economy lag behind rivals), the powertrain's durability record is exceptional. Owners regularly push past 200,000 miles with straightforward maintenance. The Double Cab body gives you a full-size rear seat that's genuinely usable for adults, an 8-foot bed option, and a towing rating of up to 10,400 lbs. It's a working truck first — not the most refined ride on the highway, but it more than earns its keep when you actually put it to work. For Lake Geneva-area owners, the main caution is the salt belt: Wisconsin roads are hard on underbodies, and the Tundra's frame and exhaust components need proactive attention each fall and spring. Budget for annual undercoating and keep up with those fluid changes, and this truck will reward you with a decade-plus of low-drama ownership.
Known for
- Bulletproof 5.7L V8 with outstanding long-term reliability
- Best-in-class resale value among full-size trucks
- Robust 4WD system well-suited for off-road and snow
- Excellent towing and payload for everyday hauling
- Simple, proven platform that's easy and affordable to service
Best for
- Owners who tow boats, trailers, or equipment regularly
- Buyers who prioritize long-term reliability over tech features
- Drivers who want strong resale value at trade-in time
- Off-road and four-season use in the upper Midwest
Watch for
- Secondary air injection pump failure — a known, expensive weak spot on this generation
- Water pump failures that can escalate to overheating if ignored
- Frame and undercarriage rust in Wisconsin's salt belt — inspect every spring
- Outdated infotainment system prone to lag and freezing
- Fuel economy is noticeably below modern competitors (Ford, Ram, GM)
Common issues by mileage
6 knownWater Pump Failure
medium- Typically appears
- 90–130k mi
- Estimated repair
- $600 – $1,000
Random/Multiple Cylinder Misfire
medium- Typically appears
- 90–120k mi
- Estimated repair
- $150 – $500
Frame and Undercarriage Rust
high- Typically appears
- 50k+ mi (salt-belt accelerated)
- Estimated repair
- $500 – $3,000
Infotainment System Freezing / Failure
medium- Typically appears
- 40–80k mi
- Estimated repair
- $300 – $600
VVT-i Camshaft Timing Issues
low- Typically appears
- 100k+ mi
- Estimated repair
- $300 – $900
Maintenance schedule
- 1 Every 5,000 miles or 6 months Engine oil and filter change — 7.4 qts 0W-20 full synthetic
Toyota specifies 0W-20 synthetic for this engine. In Wisconsin winters, that low-viscosity cold-flow is especially important for quick lubrication on sub-zero starts. Don't stretch this interval — dirty oil is the #1 cause of VVT-i actuator problems.
- 2 Every 5,000 miles Tire rotation
The 5,670-lb curb weight accelerates uneven wear, especially on 4WD models. Rotating on the same schedule as oil changes is the easiest way to stay on top of it and extends tire life significantly.
- 3 Every 30,000 miles or 36 months Air filter replacement (OEM part 17801-0S050)
A restricted air filter on a high-displacement V8 noticeably affects fuel economy and throttle response. At Wisconsin's dusty summer road conditions and salty winter air, don't push past this interval.
- 4 Every 20,000 miles Cabin air filter replacement (OEM part 87139-0E040)
A clogged cabin filter reduces heater and defroster airflow — a real problem in Wisconsin winters when you need that defroster working hard. Easy DIY swap.
- 5 Every 60,000 miles Transmission fluid service — 11.5 qts Toyota WS ATF
Toyota WS fluid is required — don't substitute a generic ATF. The 6-speed automatic is durable but heat from towing degrades fluid faster. If you tow regularly, consider dropping to 45,000-mile intervals.
- 6 Every 60,000 miles or when coolant appears discolored Coolant flush — Toyota Super Long Life (pink)
Use Toyota SLLC or a compatible pink OAT coolant only. Mixing coolant types causes gel deposits that can clog the radiator and accelerate water pump wear. Capacity is 14.9 qts.
- 7 Every 60,000–90,000 miles Spark plug replacement
The 5.7L V8 has 8 cylinders and iridium plugs. Worn plugs on a high-displacement engine like this cause rough idle, misfires (P0300), and reduced fuel economy. Don't let them go past 90k.
- 8 Every fall (before first freeze) Full undercarriage inspection and undercoating touch-up
Lake Geneva sees heavy road salt from October through March. An annual inspection of the frame, exhaust hangers, brake lines, and differential covers — followed by fresh undercoating where needed — is the single best investment you can make for this truck's long-term health in Wisconsin.
Always defer to the manufacturer's service manual for warranty-mandated intervals.
Cost of ownership
Annual maintenance
$600 – $1,200
Fuel
At ~15 MPG combined and typical driving of 15,000 miles/year, expect roughly $2,700–$3,300/year in fuel at current Wisconsin prices. The 5.7L V8 is thirsty — factor this in if you're comparing to newer half-tons with turbocharged engines.
Insurance
Full-size truck insurance in southern Wisconsin typically runs $1,200–$1,800/year for a 2021 model depending on driver profile, coverage level, and use (personal vs. commercial towing). The Tundra's strong safety record helps keep rates reasonable.
Day-to-day running costs are modest — the engine and drivetrain are simple and parts are affordable. The big wildcard is the secondary air injection pump, which will likely need replacement once in the truck's life at $1,100–$1,800. Fuel is this truck's largest ongoing cost given the 5.7L's appetite. Budget $2,500–$3,500/year all-in for maintenance and fuel outside of any surprise repairs.
Seasonal care
Lake Geneva, WI Winter
- Switch to a full synthetic 0W-20 oil if not already running it — the low viscosity matters on cold Wisconsin mornings when the engine needs immediate lubrication at -10°F.
- Test the battery before November. Cold-cranking amps drop sharply below 20°F, and the 5.7L V8 puts heavy demand on the battery at startup. Replace any battery older than 4 years proactively.
- Fill the washer fluid reservoir with a -20°F or -30°F rated fluid. Standard fluid freezes in the lines and on the windshield — a genuine hazard at highway speed.
- Inspect wiper blades in the fall and switch to winter/beam-style blades that won't pack with snow and ice.
- Check tire pressure monthly — tire pressure drops roughly 1 PSI for every 10°F drop in temperature. Under-inflated tires hurt braking on snow and ice.
- Spray all door seals and the tailgate seal with silicone lubricant before freeze-up to prevent them from sticking or tearing.
Summer
- Inspect the A/C system early in the season — the Tundra's compressor is a known failure point on higher-mileage examples, and finding out it doesn't work in July is worse than addressing it in April.
- Check tire pressure after the first hot week of summer — pressure rises with heat and an over-inflated tire wears unevenly and has reduced grip.
- Inspect coolant level and condition before summer heat. A marginal cooling system that survived winter can overheat when towing in July. Flush if the coolant is more than 60k miles old.
- Clear any road salt residue from the undercarriage with a thorough pressure wash in spring — salt stays active and corrosive even after it dries.
Comparable vehicles
No comparable vehicles documented yet.