How much power, which parts, and where to buy them.
Every car on this sheet gets the same four stages: software, breathing parts, a bigger turbo, and a built engine. For each stage I list what the tuners claim, the parts you actually need, and the brands that make them.
No guessing and no made-up dyno numbers. If a figure is on this site, it comes from the company that sells the tune.
Featured builds
Finished guides first, then the cars coming next. Swipe or use the arrows.
The sheet
| # | Generation | Engine | Stock | Stage 1 | Stage 2 | Stage 3 | Stage 4 |
|---|
Nothing matches that yet. Cars are added every week.
Peak horsepower as claimed by the tuners, on the best fuel each tune supports. Stage 4 is a typical built-engine range.
Before you tune
Every tune is written for a specific octane. Check which fuel you can actually buy near you, and ask for the file that matches it, not the one with the biggest number.
Most tuned cars that break don't break the engine. They slip the clutch or overwhelm the gearbox. Budget for a gearbox tune or clutch upgrade from Stage 2 onwards.
Only fit exhaust parts with a catalytic converter, keep your paperwork, and check what your country allows before you modify a car you drive on the road.
Where the numbers come fromEvery power figure on this site is the tuner's own published claim, linked from the guide. We note the fuel each figure needs, and Stage 4 ranges are clearly marked as community builds, not product claims.
How to use this site
- Find your exact car
Pick the generation, not just the model. An S3 8P and an S3 8V have different engines, different turbos and completely different parts.
- Decide where to stop
Most people are happiest at Stage 1 or Stage 2. Each guide shows what every step costs you in parts, and what it asks of the gearbox and clutch.
- Compare the brands
For every stage we list the tunes and parts from several companies side by side, with each company's own figures and a link to buy.
Questions people ask
What is the difference between Stage 1, 2, 3 and 4?
Stage 1 is software only. Stage 2 adds breathing parts such as a downpipe, intake and intercooler. Stage 3 means a bigger turbo on the stock engine. Stage 4 is a rebuilt engine with forged internals, a big turbo and a full fuel system. There is no official standard, so every tuner draws the lines a little differently; our guides always tell you which parts each tune expects.
Is tuning bad for the engine?
A good Stage 1 or Stage 2 tune from an established company is designed to stay within safe limits, but it does add stress. The weak points are usually the clutch, the gearbox and heat, not the engine itself. Service the car more often, use the fuel the tune was written for, and follow the gearbox advice in each guide.
Will a tune void my warranty?
It can. Manufacturers can refuse warranty claims on parts affected by a tune. Some tuners offer their own limited powertrain warranty; where they do, we mention it in the guide.
Why do different sites show different horsepower numbers?
Some figures are engine horsepower and some are measured at the wheels, and they depend on fuel, weather and the dyno. We always use the tuner's own published figure and note the fuel it needs, so you can compare like with like.
Can I go back to stock?
Most software tunes can be flashed back to the factory file, and most bolt-on parts can be refitted with the original ones. Keep your original parts and ask the shop before you start.
How do you choose which brands to list?
We list companies that make a product for that exact car and publish clear information about it. Being listed is not a paid placement. Some links may earn us a commission, which never changes the numbers we show.
The four stages
- 1Software
A new file on the factory ECU. No parts. Usually the biggest gain per dollar.
- 2Breathing
Downpipe, intake and intercooler, plus a tune written for them.
- 3Bigger turbo
More boost on the stock engine, up to where the internals are still happy.
- 4Built engine
Forged rods and pistons, a big turbo, a fuel system and a custom tune.