What should I install?
Every upgrade slot in Forza Horizon 6 — what it actually does, what it costs in PI, when it earns its keep, and the traps that quietly burn points. Distilled from community guides and updated for FH6's heavier slick-on-dirt penalty, first-class front tire width, and the new reality that brakes are no longer optional.
Must-do rules
Homologate step-by-step →- Build before you tuneNo tune fixes a bad build. The parts decide the ceiling; the tune chases it.
- Pick discipline first, class second, drivetrain thirdEvery later choice gates on those three. Reorder them and you waste PI.
- Weight reduction is the only universally efficient upgradeThe only category rated efficient across all five disciplines. Max it as PI allows.
- Match tire compound to surface, not to classRace slicks on dirt is a deliberate FH6 PI penalty. Rally / off-road tires are not downgrades.
- Try front tire width before stepping compound upNew in FH6: front width is a first-class lever, often cheaper PI for the same gain.
- One brake tier is mandatory above D-classStock brakes lock up under hard downshifts and trail-brake in FH6.
- Race differential is the only must-have drivetrain partUnlocks the Accel + Decel + AWD center-balance sliders. The other four are budget calls.
- Power last — after the car can handle itA car that can't put down its power is slower than a car with less power and better chassis.
- Verify PWR delta before any engine swapBigger engine ≠ better car. If the post-swap PWR doesn't improve, skip the swap.
- Widebody only if you use the wider tiresOtherwise you pay drag and PI for cosmetics.
By category
Where most PI-per-grip lives in FH6. Front width is its own lever now — use it before bumping compound.
No longer optional in FH6 — stock brakes lock up under hard downshifts and trail-braking. Budget for one tier.
The only upgrade that is universally PI-efficient — improves braking, rotation, acceleration, and stability. Max it.
The "type" of suspension you install — gates which tune sliders unlock. Sport is the cheap path to full tuning.
Changes the fundamental character of the car. AWD swap is heavy PI; RWD swap from AWD usually nets nothing.
Decide on PWR delta, not displacement. A bigger engine that ruins balance is a worse car.
Power-delivery shape. Centrifugal SC is usually the most PI-efficient for road; twin turbo on small engines is a trap.
PI traps live here. Race-tier on everything stacks 15–25 PI you usually want elsewhere.
Cornering grip at the cost of top speed. Front aero is usually free; rear wing is the expensive half.
Cosmetic-looking but real weight. Pick the lightest style at the smallest diameter that fits your target tire width.
Build smells
All smells →- Race-tier on all five drivetrain partsdrivetrain-parts →Keep Race diff; downgrade transmission to Sport at B/A; skip Race clutch on non-M/C input. Reclaim 5–15 PI.
- Race slicks on a dirt or cross-country buildtires →Switch to rally or off-road compound — FH6 made this a hard PI penalty.
- No brake upgrade above D-classbrakes →Add one Sport brake tier. 2–5 PI, fixes lockup and trail-brake understeer.
- Widebody installed without wider tires or aero useaero-body →Remove widebody — you're paying drag and PI for cosmetics.
- AWD swap on a light low-class cardrivetrain-conversion →Revert to factory drivetrain; spend the 30–80 PI on tires and weight.