Frequently Asked Questions About Kenworth T300-T450 Engine & Performance Parts

Will these engine parts fit my specific Kenworth T300, T350, T400, or T450 model year?

Most engine and performance parts for Kenworth T300-T450 models are compatible across years 1994-2010, but critical components like ECMs, turbochargers, and fuel systems can vary by engine type (Caterpillar C7, Cummins ISB, ISC, ISL, or Paccar PX-6/PX-8). Always verify your engine serial number and model year before ordering. Contact our technical support team with your VIN if you need help confirming compatibility.

What are the most common engine upgrades that actually improve fuel economy and power?

The most effective upgrades for T300-T450 trucks include high-flow air filter systems (typically improving MPG by 3-5%), performance ECM tuning (adding 20-50 HP and 10-15% better fuel economy), upgraded turbochargers, and improved exhaust systems. For pre-2007 models, EGR delete kits are popular but check local regulations. Post-2007 DPF-equipped trucks benefit most from DPF cleaning services or upgrade kits.

How difficult is it to install performance parts on these medium-duty Kenworth trucks?

Installation difficulty varies significantly. Air filters, exhaust tips, and gauges typically take 1-2 hours with basic tools. Turbocharger upgrades, fuel system modifications, and ECM programming require 4-8 hours and specialized diagnostic equipment. Most shops charge $500-$1,500 for complex installations. We recommend professional installation for any parts affecting emissions systems or requiring ECM changes.

What's the difference between OEM and aftermarket parts for reliability and warranty?

OEM parts typically carry 1-2 year warranties and guarantee exact fit but cost 30-50% more. Quality aftermarket brands like Dorman, PAI, and Interstate-McBee offer comparable reliability with 1-year warranties at lower prices. For critical components like injectors and turbochargers, OEM or remanufactured OEM is recommended. For maintenance items like filters, belts, and hoses, premium aftermarket parts perform equally well.

Which performance modifications require ECM reprogramming or will trigger check engine lights?

Any modifications to exhaust systems (DPF deletes, EGR deletes), turbocharger upgrades, or fuel system changes on 2007+ models will require ECM reprogramming to prevent fault codes. Performance air intakes and exhaust tips typically won't trigger codes. Pre-2007 models are more forgiving, but significant turbo or fuel system changes still need ECM adjustments. Budget $300-$600 for professional ECM tuning when installing major performance upgrades.