New & Used Commercial Magnum Generators For SaleIndustrial-Rated Magnum Generators

Magnum Mobile Generators for Jobsite Power

Magnum builds mobile power. Every Magnum generator that has come through our inventory is a trailer-mounted diesel unit designed to move between jobsites, set up quickly, and carry load for long stretches. That makes the brand a staple of construction sites, rental fleets, oil and gas operations, events, and disaster response. Magnum is also one of the best-known names in light towers, which often travel to the same jobsites as the generators. Browse our trailer-mounted generators for current mobile options.

Magnum Under Generac Ownership

Generac acquired Magnum Products in 2011 and kept the Magnum brand running out of its facility in Berlin, Wisconsin. Some newer MMG-series units now appear under Generac branding, and our own listings show the same MMG100D model under both names. For buyers, the model number is what matters. An MMG unit carries the same engineering whether the badge reads Magnum or Generac. Our Generac generators page shows the rest of the Generac lineup if you want to compare.

Magnum MMG Models by Size

Magnum’s MMG line covers the full range of mobile jobsite power. Here is where the models we have carried fall, based on standby ratings from our listings:

• MMG45 at 35 kW — small jobsites and light commercial use. Shop 25kW – 49kW generators.
• MMG55FH at 50 kW — mid-size jobsites with a few larger tools or pumps. Shop 50kW – 74kW generators.
• MMG80 and MMG100 at 86 kW — the most common Magnum units in the rental market. Shop 75kW – 99kW generators.
• MMG120 through MMG205 at roughly 107 to 177 kW — larger construction projects and temporary facility power. Shop 100kW – 249kW generators.
• MMG320 and MMG330 at 278 to 290 kW — heavy jobsite loads and industrial temporary power. Shop 250kW – 374kW generators.
• MMG480 at 419 kW — the top of the mobile range, with a 616-gallon onboard tank. Shop 375kW – 499kW generators.

Note that Magnum model numbers run higher than the kW rating. An MMG100 delivers 86 kW standby, not 100. Always size against the listed kW, not the model name.

John Deere Engines in Magnum Generators

Most Magnum generators we have stocked run John Deere diesel engines, with Kubota power on the smallest units. That engine consistency simplifies parts sourcing and service, since John Deere support is widely available. Larger MMG models use Deep Sea digital controllers. Common features across the line include camlock connections for fast cable hookup, 120V and 240V convenience receptacles, surge brakes, and sound-attenuated enclosures. Emissions tiers vary by model year, from Tier 3 to Tier 4i, so confirm the tier on any listing against the requirements where the unit will operate.

How Used Magnum Units Hold Value

Mobile generators depreciate quickly in their first few years, then hold value well once they have proven themselves in a rental fleet. That curve makes used Magnum equipment one of the better values in the mobile market, particularly for contractors building their own fleet rather than renting job to job. Browse our used industrial generators for current options. The tradeoff is hours. Rental units work harder than standby equipment, so engine hours and maintenance history carry more weight in the buying decision. When we cannot verify hours on a unit, we say so on the listing.

When a Used Magnum Pays for Itself

Renting fits a single project with a defined end date. Our rental division, Stag Power Rentals, handles that side of the business. Buying wins once a mobile unit stays busy. Contractors running a generator across back-to-back projects typically find that a year of rental payments approaches the price of an inspected used Magnum. Our generator financing options make the purchase easier to fit into a budget.

Verifying Magnum Fleet Units Under Load

Every Magnum generator we sell passes a 22-point inspection and load bank testing before shipment. For fleet equipment that has spent years on the road, testing under load is what separates a well-maintained unit from one that only looks the part. We have been buying and selling industrial generators for more than a decade. Every purchase is backed by our 30-day IronClad warranty. After delivery, our service team handles preventative maintenance and electrical repair. Comparing mobile brands? Multiquip generators and Doosan generators compete in the same class, and our shop by brand page covers every manufacturer we carry.

Ready to Buy a Magnum Generator?

Tell us what you are powering on site and how often the unit will move, and we will match you to the right Magnum model. Browse our full inventory of industrial generators or contact us to talk it through.