The X3 M40i and X4 M40i have the B58 and a real appetite for back roads. What they also have is SAV ride height. Carry some speed into a corner and you feel the body lean and the nose dip before the chassis catches up with the engine.
The Dinan Performance Spring Set for the G01 X3 M40i and G02 X4 M40i lowers both 7/8" (22mm) front and rear with a 25% increase in spring stiffness at each axle. The result is less body roll, less dive and squat, sharper steering and a stance that looks planted instead of perched.
How Dinan Performance Springs Tune the X3 M40i and X4 M40i
Dinan splits the design front to rear. Linear rate springs up front give consistent, precise feel on turn-in. Dual rate springs in the rear stay supple when the car is lightly loaded, then firm up when you load the back with passengers, cargo or hard acceleration. It is a setup built for how these cars actually get used.
Each spring is CNC wound from high tensile chrome silicon wire and shot-peened for stress relief, made to hold its rate without sagging.
Dinan X3 M40i / X4 M40i Springs and Ride Quality
Dinan designs these springs to be installed with the matching Dinan Ride Quality and Handling Kit, which keeps proper suspension travel at the lower height. Without it, ride quality and handling suffer, and Dinan's warranty will not cover ride or handling complaints. These fit the M40i models only, not the X3M or X4M. Dinan part number D100-0942. Sold by AutoTecknic, an authorized Dinan dealer.
What's Included
- Two front linear rate performance springs
- Two rear dual rate performance springs
- Ride Quality and Handling Kit sold separately
Key Features
- Lowers the X3 M40i and X4 M40i 7/8" (22mm) front and rear
- 25% increase in spring stiffness front and rear
- Linear rate front springs and dual rate rear springs
- Less body roll, dive and squat with sharper steering
- CNC wound high tensile chrome silicon wire, shot-peened for stress relief
- Preset to hold rate without sagging
- Designed to pair with the Dinan Ride Quality and Handling Kit
Vehicle Fitment
Fits the following B58-powered BMW models:
- BMW X3 / G01 (2018-2024): X3 M40i
- BMW X4 / G02 (2019-2025): X4 M40i
Not compatible with the X3M (F97) or X4M (F98).
Installation Notes
Dinan quotes 9.9 hours including alignment. You will be removing strut assemblies and compressing coil springs, so most owners use a shop.
- Raise the vehicle and remove the wheels.
- Remove the front strut assemblies and use a spring compressor to fit the Dinan linear rate front springs with the Ride Quality and Handling Kit parts.
- Replace the rear springs with the Dinan dual rate springs and fit the matching kit components.
- Reinstall all components, lower the vehicle and let the suspension settle, then torque the suspension bolts at ride height.
- Have a four-wheel alignment done at the new ride height.
