Koenigsegg Jesko Tuning Guide — Best Setup for FH6

Class Range: S2 - X | Base HP: 1,280 | Drivetrain: RWD | Weight: 1,420 kg | Best Class: S2

The Koenigsegg Jesko is the car I recommend when someone asks "what's the fastest thing in FH6?" and actually means it. 1,280 horsepower in a car that weighs less than a Honda Civic, with a 9-speed Light Speed Transmission that shifts so fast you'll think the game glitched. This is the car that holds the speed trap records on every single highway in the game.

But the Jesko is also terrifying. It's RWD only — you're putting 1,600+ tuned horsepower through two rear tires. The traction circle is basically a suggestion. Get on the throttle a millisecond too early out of a corner and you're facing the wrong way. The Jesko rewards patience and punishes greed more than any other car in FH6.

The 9-speed Light Speed Transmission fundamentally changes how you tune gearing. On most circuits, you'll never see 7th gear. The transmission is so good at keeping the engine in the power band that aggressive gearing changes matter less than on other cars. You tune a Jesko by feel, not by spreadsheet.

Best Tuning Setups by Class

S2 (998) — Speed Demon

Tires: 32/32 PSI
Gearing: Speed final, 3.10
Camber: -1.2°/-0.8°
ARB: 28/25
Springs: Front 600 / Rear 500
Ride Height: Lowest
Aero: Min both
Diff Accel: 85%/15%

The classic Jesko build. Minimal drag, maximum speed. 460+ km/h on the highway. Feather the throttle out of corners or you'll spin.

S2 (998) — Circuit Racer

Tires: 29/30 PSI
Gearing: Balanced final, 3.60
Camber: -1.5°/-1.0°
ARB: 30/27
Springs: Front 650 / Rear 550
Ride Height: Lowest
Aero: 20% front, 25% rear
Diff Accel: 75%/20%

The online racing build. Enough downforce to keep the rear planted through sweepers. Still fast enough to overtake on straights.

S2 (998) — Grip Focus

Tires: 28/29 PSI
Gearing: Accel final, 3.90
Camber: -1.8°/-1.2°
ARB: 32/28
Springs: Front 700 / Rear 600
Ride Height: Low +2 clicks
Aero: 40% front, 45% rear
Diff Accel: 70%/25%

Maximum mechanical grip. Sacrifices 30 km/h top speed for cornering confidence. Use on tight circuits like Guanajuato.

Key Tuning Parameters

Suspension & Handling

The Jesko is a mid-engine RWD car with a carbon fiber tub stiffer than a tax auditor. The rear springs need to be softer than you'd expect — 500-550 lb/in rear versus 600-650 front creates natural anti-squat. The rear ARB should be 2-3 clicks softer than the front — this sounds backwards for RWD but the Jesko has so much mid-engine rotation already that stiff rear ARB just makes it snap-oversteer.

Gearing Strategy

Nine gears is too many for circuit racing. Set 7th gear as your effective top gear — adjust final drive so 7th redlines at your car's actual top speed on the longest straight. Make 2nd gear slightly taller than you think — prevents wheelspin on corner exit, worth more lap time than the slight acceleration loss.

Common Tuning Mistakes

ProblemFix
Wheelspin in 2nd and 3rd gearReduce rear tire pressure to 28 PSI, increase 2nd gear ratio (taller), lower accel diff to 75%
Snap oversteer mid-cornerSoften rear ARB by 3-4 clicks, reduce rear spring rate 50 lb/in, add 0.2° rear toe-in
Front end lifts at high speedAdd 10% front downforce, lower front ride height to minimum, stiffen front springs 75 lb/in