The short answer: The Leitner Designs ACS ROOF is the best roof rack for the INEOS Grenadier if you want maximum load capacity, a low-profile design, and the ability to add secure storage without sacrificing safari window functionality. It mounts directly to the Grenadier's roll cage — not the rain gutter — and adds just 2 inches to your vehicle's height.

If you're already invested in the Front Runner ecosystem or need the largest accessory catalog, the Slimline II is a solid alternative. But for pure engineering and load-carrying capability, Leitner leads.

Quick Specs: Leitner ACS ROOF for Grenadier

Why the Mounting System Matters

Most roof racks for the Grenadier mount to the factory rain gutter. Leitner's ACS ROOF takes a different approach: billet aluminum mounting bases bolt directly to the Grenadier's roll cage.

Why does this matter? The roll cage is a structural member. The rain gutter is not. By mounting to the roll cage, Leitner can support significantly higher loads without relying on a mounting point that wasn't designed for serious weight. Rain gutter roof rack mounts on the grenadier have been known to crack the rain gutter leading to expensive damage that is almost impossible to repair. 

This is the same engineering philosophy behind Leitner's truck bed racks, which are pursuit-rated for law enforcement use and tested to 4.0g forces.

What Makes Leitner Different

4-inch center load bar. Most roof rack load bars are 2 inches wide. Leitner's is 4 inches — twice as stiff, which means less flex under heavy loads and less vibration at highway speeds.

Adjustable sliding load bars. The load bars slide into toothed channels, so you can reposition them infinitely. Need to move your rooftop tent forward to balance weight? Takes 30 seconds.

GearPOD ROOF integration. Leitner's patented side-opening GearPOD ROOF adds 96Qt (24 gallons) of secure, lockable storage directly on the rack. Pre-marked mounting points for MAXTRAX and RotoPax mean you don't have to measure anything.

Integrated wire management. Running lights, antennas, or a Starlink? The rack has built-in channels to hide wiring, so you don't have exposed cables baking in the sun.

Wind noise reducer included. Not an add-on — it's in the box.

How Leitner Compares to Alternatives

Front Runner has the deepest accessory catalog in the industry — if you're already invested in their ecosystem, the Slimline II makes sense. But their mounting legs add significant height (225mm/~9 inches), and the rain-gutter mounting limits ultimate load capacity.

LFD Off-Road is popular in the Grenadier community and offers good value, but lacks the integrated storage system and precision engineering of the Leitner.

Which Size Should You Choose?

Choose the 3/4 Platform ($1,895) if:

• You want full safari window functionality (open and remove)

• Garage clearance is a concern

• You're prioritizing access over maximum cargo space

Choose the Full-Length Platform ($2,695) if:

• You need maximum roof real estate

• You're mounting a rooftop tent, large awning, or multiple accessories

• You can accept opening (but not removing) your safari windows

The Bottom Line

The INEOS Grenadier deserves a roof rack engineered to the same standard as the vehicle itself. Leitner's ACS ROOF — designed, engineered, and manufactured in the USA — delivers roll-cage mounting, a 4-inch center load bar, integrated storage, and the ability to run your safari windows without interference.

It's not the cheapest option. It's the strongest.

Shop ACS ROOF for INEOS Grenadier