Audi RS3 8Y or Mercedes-AMG A45 S? They're rivals, so owners often weigh one against the other. Here's how far each one goes, using the makers' and tuners' own figures from our two guides.
At a glance
| Audi RS3 8Y | Mercedes-AMG A45 S | |
|---|---|---|
| Years | 2021– (Sportback and Saloon) | 2019– (facelift 2023) |
| Engine | 2.5 TFSI five-cylinder (EA855 evo) | 2.0 turbo four M139 |
| Stock power | 401 hp / 369 lb-ft (US) | 421 PS / 500 Nm (EU) |
Power by stage
| Audi RS3 8Y | Mercedes-AMG A45 S | |
|---|---|---|
| Stock | 401 hp | 421 hp |
| Stage 1 | 446–561 hp | 450–510 hp |
| Stage 2 | 467–565 hp | 470–520 hp |
| Stage 3 | 585–613 hp | 525–600 hp |
| Stage 4 | 650–800+ hp | 600–650+ hp |
Figures are the tuners' own claims from each guide, on the fuel each tuner states.
Typical parts cost
| Audi RS3 8Y | Mercedes-AMG A45 S | |
|---|---|---|
| Stage 1 | APR $1,200 plus a $1,000 unlock; Unitronic's unlock alone $560 (software through dealers); plug-in modules €479–€609 (RaceChip), $679 (JB4) and $1,499–$1,949 (MTM); HGP €5,800 and ABT Power S €6,090 including VAT. | $1,499–$2,580 (Eurocharged, Weistec, RENNtech); gearbox tune $1,000 more; RaceChip €609; EST with a new CPC £1,550 including VAT. |
| Stage 2 | APR $1,300 plus the unlock; HGP €8,500 plus €1,000 fitting; ABT Power R €9,151 including VAT. | Weistec downpipe $899 or Milltek £990; water-methanol kit $1,600; EST Stage 2 £2,150–£3,750. |
| Stage 3 | HGP turbo kits €13,500–€15,500 plus €1,500 fitting; the TTE600 turbo alone €1,791 before VAT. | hybrid turbos $2,999 (Weistec) or €1,470–€4,499 before VAT (TTE, MACHGRADE); EST570 £6,995–£8,550. |
List prices from the guides, before shipping, import tax and fitting. "—" means that guide has no cost line for the stage.
Where each one ends up
At Stage 4 the Audi RS3 8Y reaches 650–800+ hp and the Mercedes-AMG A45 S 600–650+ hp.