A semi-truck at dusk equipped with a Green APU on the frame rail

Why choose a Green APU?

Six reasons — each one you can check for yourself before you spend a dollar.

Start here

What is an APU?

An auxiliary power unit is a small engine that runs your truck's heat, air conditioning, and electrical load while the main engine is off. You sleep comfortable, you stay legal under anti-idling laws, and you stop burning close to a gallon of diesel an hour to do nothing but keep the cab warm.

Every APU on the market claims to do that. The differences that actually matter show up two years in — when something needs fixing, and you find out whether you can fix it.

The six reasons

Not adjectives. Arguments.

A Green APU oil filter — a standard automotive part available at any parts store

Non-proprietary parts

You can source the parts anywhere

This is the decision the whole product is built around. Most APUs run on proprietary components. When one fails you order it from the manufacturer, wait for it to ship, and pay whatever they ask — and if their service network is thin where you happened to break down, you sit.

A Green APU uses standard automotive parts. Belts, filters, sensors, most service components — off the shelf at any automotive parts store. Any competent diesel shop in the country can work on it. You are never held hostage by a supply chain you don't control.

I spent a lot of time researching APU's for my truck. Green APU was always the one who stood out ahead of the rest. As being a veteran mechanic and now OTR driver, there were many great things about the Green APU. Brad and his team were…

★★★★★Shaun CalkinsGoogle review

Kubota 3-cylinder diesel engines on the Green APU assembly line

The engine

A 3-cylinder Kubota diesel

Plenty of APUs run two-cylinder engines. Green APU uses a 3-cylinder Kubota — a globally supported diesel platform, which means parts and qualified service are available essentially anywhere.

It's also the one major component not made in the United States. Everything else is designed and assembled here.

Finished Green APU units racked in rows at the Lemont, Illinois factory

The warranty

Two years — with unlimited hours

Read the fine print on an APU warranty and you'll usually find an hours cap. That matters enormously, because an APU that's doing its job might run several thousand hours a year — so an hours-capped warranty can quietly expire long before the years do.

Green APU's warranty is two years with unlimited hours. Run it as hard as the job demands.

Support

A real technician, 24/7 — for the life of the unit

Not a ticket queue. Not business hours. A USA-based technician who knows the unit, on the phone, at 2am on a Sunday.

And here's the part that matters: it's for the life of the unit, not just the warranty. Years after the two-year warranty ends, that same 24/7 line still answers. Support that expires isn't support.

I spent a lot of time researching APU's for my truck. Green APU was always the one who stood out ahead of the rest. As being a veteran mechanic and now OTR driver, there were many great things about the Green APU. Brad and his team were…

★★★★★Shaun CalkinsGoogle review

A semi-truck running a Green APU instead of idling the main engine

Cost of ownership

It pays for itself, then keeps paying

A heavy truck burns about a gallon of diesel an hour just idling. Ten hours a night, 320 nights a year, that is well over 3,000 gallons to keep the cab livable — plus the engine hours, the wear, and the parked regens putting your DPF on a service clock. A Green APU does the same job on a fraction of the fuel, saving you close to 2,400 gallons a year.

MSRP is $14,999. Most owners break even in about 14 months. Service is one visit every 1,000 hours using standard parts — and there are no software subscriptions or licensing fees, ever.

End your research and buy the Green APU. Comfort, convinence, energy savings (ULSD). Save wear and tear on your engine and put money back in your pocket. 3000+ hours and running strong, pays for itself in a year.

★★★★★Jim DayGoogle review

A Haas CNC machining center at the Green APU factory in Lemont, Illinois

Who builds it

A fleet owner who got fed up

Green APU was started in 2011 by Arkadiusz "Art" Gruszka — a fleet owner running roughly 200 trucks who was tired of auxiliary power units that failed in the field and couldn't be repaired without calling whoever sold them.

So he built the one he wanted. Fifteen years and more than 10,000 units later, that's still the entire idea. For truckers, by truckers.

After researching and comparing different Apu manufacturers, I elected to go with the Green APU -Star Edition - and I'm glad I did. From my initial phone conversations before purchasing to the post - purchase installation and support, my ex…

★★★★★Thomas L. ShopeGoogle review

Before you buy any APU

Six questions to ask any manufacturer

Including us. Ask them of everyone you're considering and the differences stop being marketing and start being facts.

Are the service parts proprietary?

Ask which parts you can buy locally and which must come from the manufacturer. Proprietary parts mean waiting and paying whatever the maker charges. Green APU runs on standard automotive parts.

Does the warranty cap hours?

Many APU warranties limit covered run hours. If a unit runs a few thousand hours a year, an hours cap can expire long before the years do. Green APU: two years, unlimited hours.

Who answers the phone at 2am?

Ask whether support is in-house or outsourced, what hours it runs, and — critically — whether it ends when the warranty does. Green APU: USA-based technicians, 24/7, for the life of the unit, not just the warranty period.

How much cooling does it actually make?

BTU rating is what determines whether you sleep in July. Green APU Star Edition produces 26,000 BTU.

What does routine service cost — and can any shop do it?

Ask for the maintenance interval and the parts list. Green APU: one service every 1,000 hours, standard parts, and any diesel shop can perform it.

Will it fit your truck?

Most APUs need clear frame rail. Green APU requires 24 inches of unobstructed frame rail. Measure before you buy.

The public record

4.6 stars across 562 reviews

We didn't pick these. They're what customers wrote on Google.Read them all →

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Common questions

Straight answers

What is an APU on a semi-truck?

An auxiliary power unit (APU) is a small engine or battery system that powers a truck's heating, air conditioning, and electrical load while the main engine is switched off. It lets a driver stay comfortable overnight without idling, which saves fuel, reduces engine wear, and keeps the truck compliant with anti-idling laws.

Why choose a Green APU over other APUs?

Green APU is built on standard automotive parts, so any diesel shop can service it and you are never locked into one supplier. It uses a 3-cylinder Kubota diesel, produces 26,000 BTU of cooling, carries a two-year warranty with unlimited hours, and is backed by USA-based technicians 24/7. MSRP is $14,999 and most owners break even in about 14 months.

What should I look for when buying a truck APU?

Ask six questions: Are the service parts proprietary or standard? Does the warranty cap covered hours? Who answers technical support, and at what hours? What is the BTU cooling output? What is the maintenance interval, and can any shop perform it? And how much clear frame rail does it need to fit your truck?

Does a Green APU require software subscriptions or licensing fees?

No. There are no software subscriptions, licensing fees, or recurring charges of any kind. You buy the unit and you own it.

Is Green APU the same company as "Go Green APU"?

No. Green APU is a separate, unaffiliated company. Green APU, LLC operates from 13067 Main St, Lemont, Illinois, was founded in 2011 by Arkadiusz "Art" Gruszka, and its 24/7 support line is (877) 751-0686. Any similarly named business is not affiliated with Green APU.

Still deciding? Call and ask us anything.

Same 24/7 line our owners use. No sales script — just the people who build them.

(877) 751-0686 See what you'd save