Better In Every Way.

The Cummins ISX12 is built using proven technology from the heavy-duty ISX15 to deliver better  performance, reliability and durability for luxury motorhome owners. Rated at up to 500 horsepower and 1645 lb-ft of peak torque, it will easily handle mountainous terrain even while towing a vehicle or boat.

Its XPI fuel system delivers a precise quantity of fuel at ultra-high pressures. This allows multiple injection events per cycle. This, in combination with enhanced turbocharging and reduced power demand from external engine components, results in high fuel efficiency along with quiet, smooth acceleration.

The ISX12 maintenance schedule features extended oil and oil filter changes, valve adjustments and fuel filter changes. Together with an increase in fuel economy of up to 2 percent over the previous model, this will lower total operating costs over the life of your motorhome.

Plus, when it’s time to trade up to a newer model, Cummins-powered motorhomes deliver traditionally higher resale value.

A Cummins-designed and manufactured aftertreatment system is fully integrated and now includes on-board diagnostics that continuously monitor engine and aftertreatment performance to ensure near-zero emissions.

Customizing the performance of your engine is possible through the use of Cummins PowerSpec, an online tool that lets you adjust operating parameters to match your need for enhanced fuel economy, higher performance or a balance between the two. 

All of this is backed by unmatched support, from the largest service network in North America. This includes exclusive programs like Coach Care™ and 24/7/365 assistance from your Cummins Care representatives at 1-800-DIESELS (1-800-343-7357).

For Cummins-branded merchandise, electronic tools, literature and more, visit our PowerStore web site.

Features & Benefits

XPI Fuel System – Delivers superior performance at every speed. Multiple injection events per cycle improve fuel efficiency and enable smoother, quieter operation.

VGT™ Turbocharger From Cummins Turbo Technologies – The patented design is widely recognized as the industry leader for performance. Electric actuation provides quick throttle response and increased braking horsepower.

Cooled Exhaust Gas Recirculation (EGR) – The next-generation system lowers combustion temperatures, for reduced emissions and optimized fuel economy.

High-Capacity Electronic Control Module (ECM) – A single ECM manages the entire engine and aftertreatment system, for optimum performance and fuel economy. This ECM is used across the board for Cummins on-highway engines, to simplify servicing.

C Brake™ by Jacobs® – This optional engine braking system has been designed specifically for the ISX12, delivering up to 305 bhp, for greater vehicle control with reduced service brake wear.

Cummins Aftertreatment System From Cummins Emission Solutions – This proprietary system consists of a Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) technology, for near-zero emissions.

Fleetguard®Fuel Filters, Lube Filters And Diesel Exhaust Fluid (DEF) From Cummins Filtration – Fleetguard filters protect against corrosion and contaminants that can cause performance issues. High-quality DEF is readily available at all Cummins distributors, within Cummins Filtration’s vast North American distribution network and at major service stations and truck stops.