Naming
Audi naming explained: what do 35 TFSI, quattro, S line, and RS mean?
Decode an Audi name: the A and Q families, the two-digit power index that replaced displacement, TFSI and TDI, quattro, and the difference between S line, S3, and RS3.
Updated in 2026
Direct answer
How do you read a Audi name?
In “A3 35 TFSI”, the A3 gives the family and size, the 35 is a power index introduced in 2017 — it matches no displacement — and TFSI means turbocharged direct-injection petrol. Everything after that describes trim and drivetrain.
- Read the letter and number: A for saloons, Q for SUVs, the number gives the size.
- Read the two-digit number: it is a power level, never a displacement.
- Read the four letters: TFSI for petrol, TDI for diesel, e-tron for electric.
- Separate trim from version: S line is a pack, S3 and RS3 are different cars.
Why these names look unreadable
Audi has the longest name of the three German brands, and for good reason: it stacks four independent pieces of information — family, power, energy, and trim. Taken one at a time, each block is simple.
The difficulty lies elsewhere. Audi changed how it names power in 2017, while millions of cars named under the old rule were already on the road. Two systems now coexist, and one of them lies about what it describes.
“A3 Sportback 35 TFSI S line quattro” piece by piece
| Piece | What it means |
|---|---|
| A3 | The family and rank. A covers saloons and hatchbacks, from A1 to A8; the number gives size and positioning. |
| Sportback | The body style. Avant is the estate, Limousine the three-box saloon, Allroad the raised estate. Careful: Sportback does not mean the same thing across families, see below. |
| 35 | The power level, on a scale from 30 to 70. Roughly: 30 around 110 to 130 hp, 35 around 150, 40 around 190 to 200, 45 around 250, 50 around 285, 55 around 340. This number has nothing to do with displacement: see below. |
| TFSI | The energy: TFSI for turbocharged direct-injection petrol, TDI for diesel, TFSI e for plug-in hybrid, e-tron for electric. |
| S line | A trim, not an engine. Specific bumpers, wheels, upholstery, and steering wheel, available on any engine in the range. |
| quattro | All-wheel drive. The equivalent of BMW’s xDrive and Mercedes’ 4MATIC — with an important technical nuance, detailed below. |
The families: what the letter and number say
| Letter or number | Family |
|---|---|
| A1 à A8 | Saloons and hatchbacks, from city car to flagship. |
| Q2 à Q8 | The SUVs, on the same scale as the A range: a Q3 matches an A3 in size, a Q7 an A7. |
| TT / R8 | The sports coupé and the mid-engine supercar, the only models with their own names. |
| e-tron | Electric. First a standalone model, now a suffix attached to the family: Q6 e-tron, e-tron GT. |
| S / RS | The two performance levels, not to be confused with the S line trim. |
Examples in photos
A few Audis from the ScanRacer library, each illustrating one piece of the name:
Where the rule no longer holds
The two-digit number describes no mechanics. Until 2017 an Audi wore its displacement: 1.8 TFSI, 2.0 TDI, 3.0 TFSI. Since then the badge shows a power index. A 35 TFSI is not 3.5 litres, it is a 1.5 making 150 hp. And a 40 TFSI has little in common with a 40 TDI: same rank, unrelated engines.
The “e-tron” badge changed status along the way. It first named one specific car, the electric SUV launched in 2018, before becoming a range suffix. That first e-tron was later renamed Q8 e-tron: the same car carries two names depending on its year, and both are on the road.
“quattro” covers several different systems. On longitudinal-engine models it is a permanent Torsen differential. On transverse platforms it is a Haldex clutch that only drives the rear when needed. And quattro ultra deliberately disengages the rear axle to save fuel. Two quattro Audis do not necessarily behave alike.
“Sportback” contradicts itself across families. On an A3 it means a five-door hatchback. On an A5 or Q8 it means a coupé roofline. Same word, two unrelated bodies.
The suffixes worth knowing
| Mention | Meaning |
|---|---|
| TFSI | Turbocharged direct-injection petrol. |
| TDI | Direct-injection diesel. |
| TFSI e | Plug-in hybrid. |
| e-tron | Electric. |
| quattro | All-wheel drive. |
| S tronic | Dual-clutch automatic gearbox. Tiptronic is a torque-converter automatic. |
| Avant | Estate. |
| Allroad | Raised estate, for rough roads. |
| S line | Sporty styling trim, on any engine. |
The trap: S line, S3, and RS3 are three different things
This is the most common Audi mix-up, and it comes from three uses of the same letter.
“S line” is a trim: reshaped bumpers, wheels, seats, and steering wheel. It can be ordered on any engine, including the most modest in the range. An S3, S5, or S6 is a different car, with its own engine and a revised chassis. An RS3 or RS6 comes from Audi Sport — RS for RennSport, German for racing sport — with widened track and an engine found nowhere else in the range.
In the field, three cues settle it: fender width, very visible on an RS3 or RS6 next to the standard car, exhaust tip shape — oval and generous on RS models — and the badge itself. “S line” is spelled out on a fender or grille plaque; a version “S” or “RS” is attached to the model number.
Codes like B8, C7, 8V: the generation the name hides
Like its rivals, Audi keeps the same commercial name for decades. Enthusiasts therefore use internal platform codes, with one letter per family and a number per generation.
The logic is readable once you know it: B for the A4, C for the A6, D for the A8, and a separate numbering for the A3. Saying “a B8” rather than “a 2010 A4” avoids mixing up two generations whose bodies look very much alike.
| Code | Generation |
|---|---|
| B5 à B10 | The successive A4 generations, the most cited family. |
| C5 à C8 | The A6 generations, with their matching S6 and RS6. |
| 8L / 8P / 8V / 8Y | The four A3 generations, in chronological order. |
| D2 à D5 | The A8 generations, the flagship. |
To go further on dating a model, the dedicated guide covers the cues that separate two close generations.
Frequently asked questions
What does TFSI mean on an Audi?
TFSI marks a turbocharged direct-injection petrol engine. Its diesel counterpart is TDI, the plug-in hybrid is written TFSI e, and electric is e-tron.
What do 35, 40, and 45 mean on an Audi?
It is a power index introduced in 2017, not a displacement. Roughly: 35 around 150 hp, 40 around 190 to 200 hp, 45 around 250 hp. A 35 TFSI is a 1.5-litre, not a 3.5.
What is the difference between S line, S3, and RS3?
S line is a styling trim, orderable on any engine. The S3 is a performance version within the range. The RS3 comes from Audi Sport, with its own engine and track width. Only the last is a performance car in the strict sense.
What does quattro mean?
It is Audi’s trade name for all-wheel drive. Note that it covers several different systems depending on the platform, from a permanent Torsen differential to a Haldex clutch that only drives the rear when needed.
Why don’t an A3 Sportback and an A5 Sportback share a shape?
Because the word means different things depending on the family: a five-door hatchback on the A3, a four-door coupé roofline on the A5 and Q8.
And if all you have is the car in front of you?
A badge can be removed, swapped, or added: it is one of the most common modifications. When the name is missing or looks wrong, the car itself remains — its silhouette, lights, and grille. That is where photo recognition takes over from decoding.