BMW E90 First Mods: The Ultimate Beginner's Guide
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So you've just picked up a BMW E90 — congratulations. Whether it's a 320i, 325i, 330i or 335i, you've got one of the best driver's cars of its generation. Now the real fun begins.
This guide covers the best first modifications for your BMW E90: upgrades that deliver real results, won't break the bank, and set the foundation for everything that comes next. Every mod on this list has been personally tested by our team on our own E9x builds.
1. Performance Air Intake
Why it's a great first mod: An upgraded air intake is the most popular first modification for any E90 — and for good reason. It's affordable, easy to install, and delivers a noticeable improvement in throttle response and engine sound. On the N54 335i, a cold air intake can also support modest power gains.
What to look for: A cold air intake routes cooler air from outside the engine bay, which is more dense and oxygen-rich than the warm air near the engine. This translates to better combustion and a more responsive throttle.
👉 Shop BMW E9x Air Intakes
2. Exhaust Upgrade
Why it's a great first mod: The E90's stock exhaust is quiet and restrained — which is fine for daily driving, but leaves a lot of character on the table. A cat-back exhaust system transforms the sound of your straight-six without requiring any engine modifications.
What to look for: A cat-back system replaces everything from the catalytic converter back. It's a bolt-on upgrade that's fully reversible and won't affect your warranty on most setups.
👉 Shop BMW E9x Exhaust Systems
3. Coilovers or Lowering Springs
Why it's a great first mod: The E90's factory suspension is tuned for comfort and compliance. Upgrading to coilovers or lowering springs sharpens the handling, reduces body roll, and gives your car a more aggressive stance.
- Lowering springs are the budget-friendly option — they lower the car 20–40mm and improve handling without sacrificing too much ride comfort.
- Coilovers give you full adjustability over ride height and damping, making them the preferred choice for enthusiasts who want to fine-tune their setup.
👉 Shop BMW E9x Suspension Upgrades
4. Suspension Bushings
Why it's a great first mod: If your E90 has some miles on it, the factory rubber bushings are likely worn — and worn bushings mean vague steering, understeer and a generally imprecise feel. Upgrading to polyurethane bushings restores the chassis precision the E90 was designed to deliver.
Start with: Front control arm bushings and rear subframe bushings for the biggest improvement in feel.
👉 Shop BMW E9x Bushings & Chassis
5. Front Lip or Exterior Aero
Why it's a great first mod: Not every mod has to be mechanical. A front lip spoiler is one of the most cost-effective ways to transform the look of your E90 — adding visual aggression and a hint of aerodynamic function. Carbon fiber options are lightweight and premium; polyurethane lips are more forgiving in daily use.
👉 Shop BMW E9x Exterior & Aero
Where to Start: Our Recommended Build Order
If you're working with a budget, here's the order we'd recommend:
- Air intake — immediate feel and sound improvement, low cost
- Suspension bushings — restores chassis precision, especially on higher-mileage cars
- Lowering springs or coilovers — transforms handling and stance
- Exhaust — completes the sensory experience
- Exterior aero — the finishing touch
Final Thoughts
The BMW E90 is one of the most rewarding platforms to modify — there's a huge aftermarket, strong community support, and the car responds well to even modest upgrades. Start with the basics, drive the car, and let the build evolve naturally.
At e9x Performance Parts, every product we sell has been tested on our own builds. If you have questions about fitment or which upgrade is right for your specific E90, feel free to reach out.