Quick take
Both the Kenworth T680 and Peterbilt 579 are top-tier aero tractors built on PACCAR platforms (MX engines, similar AMT options, comparable aero kits). In Greater Toronto Area duty—crowded 400-series highways, tight shipper yards, frequent stop-and-go—the “best” choice comes down to spec match + clean uptime history + a payment structure that fits your lanes.
Are you looking for a truck? Browse our used inventory.
What matters in the GTA (ranked)
- Aftertreatment reliability for urban idling and frequent regens.
- Axle ratio vs. cruise RPM at 95–105 km/h (401/407 corridors).
- AMT calibration (creep/low-speed shift logic in traffic).
- Visibility & turning for Mississauga/Brampton yards and urban docks.
- Aero package (skirts, roof/chassis fairings, bumper close-outs, APUs).
- Driver comfort (noise, HVAC, bunk quality) to cut turnover.
Run each spec’s payment impact in minutes with the Calculator.
Head-to-head: fit for GTA work
| Factor | Kenworth T680 | Peterbilt 579 | GTA Angle |
| Engines | PACCAR MX-13 common; some Cummins variants | PACCAR MX-13 common; some Cummins variants | Prioritize aftertreatment paper trail over badge |
| Transmissions | Eaton Endurant/Ultrashift or PACCAR AMT | Eaton Endurant/Ultrashift or PACCAR AMT | Low-speed AMT logic matters more than brand |
| Cab & Ergonomics | Driver-centric dash; quiet cab | Spacious feel; excellent visibility | Test both for driver fit/retention |
| Aero Packages | Competitive aero (skirts, roof fairings, close-outs) | Competitive aero (skirts, roof fairings, close-outs) | Spec full aero for 401 fuel savings |
| Serviceability | Strong GTA dealer network | Strong GTA dealer network | Pick the unit with cleaner ECM/service history |
Bottom line: On paper they’re peers. For GTA operations, pick the cleaner ECM + aftertreatment history, the right axle ratio (often 2.64–2.85 depending on tire size and target speed), and ensure AMT behaviour is smooth in city traffic.
Fuel & drivability: practical, numbers-first guidance
- Cruise RPM targeting: For direct-style top gears, many fleets aim ~1,150–1,250 RPM at 100 km/h; for overdrive, permissible RPM can be slightly lower. Verify with your tire rev/mile and the final drive ratio.
- Aero + tires compound: Full aero + low-rolling-resistance tires can swing ~0.3–0.6 MPG (0.13–0.26 km/L). On typical annual mileage, that’s a meaningful fuel-line change.
- Idle control: High idle % (winter bunk time, yard staging) increases regen counts. Prioritize APUs/idle-reduction and documented DPF/DOC service.
- AMT creep & hill logic: Toronto traffic punishes clutches; test creep mode, take-off smoothness, and downshift logic on mild grades.
For spec strategy by lane and payload, see our Heavy-Duty Truck expertise and Transportation & Trucking.
Inspection & ECM data: where decisions get made
Before you fall in love with a badge or bunk, verify the data that predicts downtime.
Pre-purchase inspection (both models)
- Aftertreatment: Pull codes; check DPF ash load, DOC health, SCR/NOx sensors; review regen frequency.
- Cooling/air: Pressure test, CAC integrity, hose/clamp condition (boost leaks kill economy).
- Driveline: U-joints, carrier bearing, vibration under load.
- Brakes/tires/suspension: Even wear, bushing health, air leaks.
- Electrical/HVAC: Alternator output, battery load test, bunk HVAC performance.
- Cab & seals: Moisture test; look for prior water ingress.
If day-1 work is needed, spread costs with Truck Repair Financing.
ECM “truth layer” (pull it every time)
- Active/inactive codes; regen counts; idle %; average speed.
- Fuel-burn trend (by duty cycle); clutch wear index (AMTs).
- DPF/NOx sensor counters; evidence of recent resets with matching invoices.
- Mileage vs. hours (city tractors age by hours).
T680 vs 579: decision cheat-sheet for GTA lanes
| Your Priority | Lean T680 When… | Lean 579 When… | Shared Must-Haves |
| Uptime (DPF/DEF history) | Verified DPF service + stable regen counts | Verified DPF service + stable regen counts | Invoices matching ECM counters |
| City drivability | AMT calibration shows smooth creep & hill logic | AMT calibration shows smooth creep & hill logic | Test in stop-and-go + docks |
| Highway economy | Right ratio + full aero + LRR tires | Right ratio + full aero + LRR tires | Target 1,150–1,250 RPM @ 100 km/h |
| Driver retention | Quiet cab + preferred ergonomics | Spacious feel + visibility | Bunk HVAC & storage that drivers like |
Finance it to fit GTA cash flow (don’t overpay for the wrong structure)
Choose the structure that matches how long you’ll keep the tractor and how quickly you need to scale.
| Option | Best For | Cash-Flow Feel | End of Term | Learn More |
| Equipment Loan | Own & keep 5–10+ years | Fixed payments; build equity | Own free & clear | Equipment Loans |
| Equipment Lease | Lower monthly / upgrade path | Residual lowers payment | Buy, upgrade, or return | Equipment Leases |
| Equipment Line of Credit | Multiple units over the year | Draw/repay as needed | Reusable facility | Equipment LOC |
| Refinancing & Sale-Leaseback | Unlock equity in owned trucks | Lump sum + new payment | Buyout or upgrade | Sale-Leaseback |
| Trailer Financing | Add dry van/reefer/flatbed | Keep tractor cash flow separate | Ownership or buyout | Trailer Financing |
If AR is slow on GC/shipper work, keep the tractor on a loan/lease and bridge gaps with a Working Capital Loan or Invoice/Freight Factoring.
24–48h approval checklist (copy/paste)
- Vendor quote with make/model, year, kms/hours, serials, attachments
- 3–6 months business bank statements (PDFs; all operating accounts)
- One paragraph on routes/payloads, start date, expected utilization
- Insurance broker contact (binder listing lender as loss payee)
Start your file here: Equipment Financing.
Case study (GTA fleet add)
A Mississauga carrier compared a T680 and a 579 for Brampton–Kingston mixed lanes. The 579 had cleaner DPF/NOx history and a ratio that held cruise near 1,150–1,250 RPM on the 401. We modeled a lease with 10% buyout via Equipment Leases, cutting the monthly ~11% vs a comparable loan and reserving cash for day-1 tires using Truck Repair Financing.
Outcome: Zero unplanned downtime in the first quarter; fuel met target.
FAQ
Which is more fuel efficient in the GTA?
They’re both aero leaders; ratio + aero + tires + driving swing MPG more than brand.
Is the PACCAR MX-13 reliable for city/regional work?
Yes—with documented aftertreatment maintenance (DPF cleans, DEF components, sensor history).
AMT or manual for Toronto traffic?
An AMT with good low-speed logic reduces fatigue and protects clutches in stop-and-go.
Can I finance used units?
Yes—see Equipment Loans and Equipment Leases.
What if I need a trailer later?
Open an Equipment Line of Credit and add Trailer Financing.
How do I estimate my payment?
Use the Calculator, then Contact Us for a firm quote.
Verdict for the GTA
Pick the unit with the best history, ratio, and AMT behaviour—not the logo. Then finance it to fit your cash flow so you can scale routes without starving operations.
Browse inventory, model payments in the Calculator, and connect with our credit analysts for a 24–48h approval. Learn more About Us.
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