Skip to main content
Price opinion from advertisements and recorded sales. Not an inspection or a certified valuation.
CarQuant page
CarQuant
Get a report
Reference photograph of a Porsche 928 S4
Valuation · Porsche · n/a · 1987-91

Porsche 928 S4

5.0L NA V8 · 235 kW / 430 Nm · 5sp manual · RWD
AVOIDRated within the $30k to $100k band · 87 of 94 at this money
Model value
$70,000
Must gain each year to break even
+10.1%
The projection does not clear it, and nor does most of the library.
CarQuant score
47/100
Scored against the $30k to $100k band, not the whole library
Evidence grade
Thin
One to three recorded Australian sales
$70,000
$46,599 lowhigh $94,128
Calibrated to a thin record
One publishable Australian result: $56,000 for a 1988 S4 coupe at Shannons in November 2020. A second Shannons figure of $21,250 carries no date, no odometer and no car identity.
Measured across this library, a value resting on a single Australian result runs high about six times in ten, by a median of five per cent.

Looking at a 928 for sale?

Put in the asking price and the odometer reading. You will see what this model should make at that reading.

Should make, typical example
$70,000
At about 55,000 km. Enter an asking price to compare.

Odometer only. Colour, options, history, condition and the photographs move it further, and that is what the report reads.

A person reads the advertisement and its photographs. Usually back within 48 hours. Read a real listing report

Price history

Today $70,000 · modelled median at five years $72,621
Solid line: the value this library has carriedDashed from 2026: modelled · even money $58,933 to $83,934
The green band is the even-money range and the one to plan on: half of outcomes land inside it. The pale band behind it bounds eight in ten ($46,599 to $94,128). The path is this model's own: it starts along the momentum of its recorded history and bends toward its projected median as the horizon lengthens, so no two cars share a future curve.

The verdict

The numbers argue against it. Scores 47/100, ranking 87 of 94 in the $30k to $100k band. Ownership economics is the strongest input, risk resilience the weakest.
Running it costs about $7,490 a year (10.7% of value), which is what the economics score measures. All in, including the projected value change, it is $7,890 a year.
The model's five year median is $72,621, a +3.7% move, with the tenth percentile at $46,599.
Value calibrated to a thin record. Treat the level as provisional.
Evidence
Thin1 recorded sale
Off its peak
at peak
Value band
wide
At least one recorded transaction plus a source. Direction is sound, the exact level less so.
Scored against every recent Australian sale this library holds, half its values land within 11.2 per cent of the price paid and the rest miss by more, in either direction. Projections are therefore damped toward flat in proportion to how little is known, and the plausible band is never narrower than the error the model is known to make.
Short term (1-5 years)$7,890 a year all in, +3.7% median value move
Long term (10-15 years)Scarcity case already formed
Negotiate from$70,000

Recorded sales

Every recorded observation, and when
2 rows on record
Every row, with its price and note (2) ↓
Nov 2020Shannons$56,000Sold
SOLD. 1988 Porsche 928 S4 Coupe, Shannons Spring Online Auction closed 18 Nov 2020.
UndatedShannons$21,250Context, excluded
SOLD but CAR AND DATE UNKNOWN. 'Porsche 928 S4 Coupe - Sold: $21,250' from Shannons' Similar Vehicle Sales panel on the archived 1989 928 S4 lot from the 2019 Sydney Autumn Classic auction. Real published Shannons money, but it is not that lot's result and carries no date or odometer. No date is published against this figure and it is excluded from this record, which is a dated series; it is shown because it is real published money.
1 completed Australian sale of 2 rows. Rows marked asking, no sale, or context are shown for honesty but do not count toward the evidence grade: an ask is not a transaction, a pass-in is a refusal, and a provenance or overseas result does not price the ordinary local car. The badge on every row is computed by the same rule as the grade, so the two cannot drift apart.

Score breakdown

Against the $30k to $100k band median
94 cars in band · ink tick marks the median
Ownership economics30% of total
57/100+2
Scarcity25% of total
55/100+2
Demand durability20% of total
46/100-20
Liquidity15% of total
42/100-10
Risk resilience10% of total
3/100-33
Sub-scores run 0-100 before weighting; the weighted total is 47/100. Medians are computed live from the 94 cars currently in the $30k to $100k band, so this picture moves when the library does.
The working behind each factor: baseline and drivers ↓
Ownership economics30% weight
57/100
Baseline84 pts
− 10.7% of value a year to run-27 pts
Sub-score (baseline plus drivers, clamped 0-100)57 pts
Scarcity25% weight
55/100
Baseline20 pts
+ 275 survivors estimated in Australia+35 pts
Sub-score (baseline plus drivers, clamped 0-100)55 pts
Demand durability20% weight
46/100
Baseline44 pts
+ An Australian-delivered manual S4 is genuinely rare+12 pts
+ The only car here yet to complete a full up-cycle locally+8 pts
− A 1,600kg V8 grand tourer is a specialist taste-10 pts
− Cheap imported automatics dominate what turns up-8 pts
Sub-score (baseline plus drivers, clamped 0-100)46 pts
Liquidity15% weight
42/100
Baseline12 pts
+ 100 days on market+17 pts
+ 27 sales a year+13 pts
Sub-score (baseline plus drivers, clamped 0-100)42 pts
Risk resilience10% weight
3/100
Baseline44 pts
− A snapped cam belt writes the engine off at $35,000-16 pts
− Automatics have barely moved while manuals firmed-10 pts
− One dated Australian result, from November 2020-8 pts
− Thin transaction record-7 pts
Sub-score (baseline plus drivers, clamped 0-100)3 pts
Model output, not advice or a valuation. Verify independently before acting.

What it costs to own · about 2,500 km a year

Annual cost of access, excl. fuel
$7,490a year
Share of value per year
10.7%
Scheduled servicing$1,69023%
Tyres, annualised$1,15015%
Registration and CTP$90012%
Insurance$2,13028%
Sinking fund (failure table)$1,62022%
All-in annualised (a different number)
Purchase (model value plus duty)$72,800
Running costs × 5 years$37,450
Median exit, net of selling cost$70,801
All-in annualised over 5 years$7,890/yr
Share of value per year11.3%
Cost of access is what the car costs to run. All-in annualised adds depreciation, duty and selling costs across a five year hold. They answer different questions and are labelled separately for that reason.
Break-even appreciation, 5 year hold
10.1%a year, only to get the money back
This library projects
+0.7%a year
The projection falls 9.4 points a year short of the hurdle. On these assumptions this car is a cost, not an asset, which can be an entirely rational thing to buy but should be bought knowing it.
Purchase$70,000
Stamp duty$2,800
Running costs x 5 years$37,450
Selling cost at exit, 2.6% of the salescales with price
Sale price needed at +5 years$113,193
Storage
Bought at
No forecast is used to compute the hurdle. It is the purchase, the duty, any premium and 5 years of running cost, grossed up for the cost of selling and spread back over the hold. The projection it is measured against is the weakest number in this product and is drawn that way in the chart above. Transport, finance and any restoration spend sit outside it.

Specification

Engine5.0L NA V8
Power / torque235 kW / 430 Nm
0-100 km/h5.9 s
Transmission5sp manual
DriveRWD
Kerb weight1,600 kg
Built worldwide15,682
Delivered to Australia150
Effective AU survivors275
Australian sales / year27
Typical days on market100 days
Launch priceNot established

What moves the price on this model

Colour hierarchy
Original paint, unresprayed+6%
A documented factory colour with the matching interior+3%
Resprayed or colour-changed-8%
Options
Five-speed manual rather than the automatic+65%
Australian delivery rather than a 2010s import+20%
Documented cam belt, water pump and tensioner+12%
Odometer sensitivity±1.8% per 10,000 km vs 55,000 km
Applied on top of these

Condition, history, originality, ownership, delivery and modification multipliers apply to every car in the library. They are applied automatically when an advertisement is analysed, and the schedule is set out once, on the analyser page.

Projected value in five years

Projected value at five years
$72,621
+3.7% on today
The model's figure. Today it is $70,000.
Even odds it lands between $58,933 and $83,934.
$46,599 lowhigh $94,128
The shaded range is even money and 42% wide; the outer figures bound eight outcomes in ten. Band width follows the evidence - a model with a tight measured record carries a tight band.
A weaker five year outlook than 55% of the library.
-26.6% weakest projected move in the librarystrongest +73.1%
Five-year cost of ownership
Value change alone: +$2,621 across five years.
Running costs over the same period: $37,450.
Duty and expected selling costs: $4,620.
Net cost of five years of ownership: $39,450, or $7,890 a year.
The projected value rise offsets part of the running cost. It does not make the car free to own.

The case for and against

The case for

Manual S4s have firmed noticeably since 2021 while automatics have barely moved, and this is the only car in the tranche yet to complete a full up-cycle in Australia. An estimated 100 to 200 were delivered new here and manual over automatic is worth 50 to 80 per cent, the largest transmission premium in this set.

The case against

An estimated 35 to 50 per cent of the local pool is cheap British and Japanese automatics landed in the 2010s, and the rough end of this market is $16,000. A snapped cam belt writes off the engine at $35,000, which exceeds the value of most surviving cars.

Known faults and risks

Risk 1Cam belt service history is effectively the whole purchase decision
Risk 2Automatics trade 50 to 80 per cent behind manuals and dominate the local pool
Risk 3Torque tube bearings, air conditioning and a seized viscous fan coupling
Engine written off by a snapped cam belt - the repair exceeds the value of most surviving cars$35,000
Torque tube bearings, driveline whine and vibration$7,000
Clutch on a manual, gearbox and torque tube out$6,500
Air conditioning - full R134a conversion and evaporator$6,000
Electrics - windows, central locking, dash pixels and the viscous fan coupling that cooks the engine when it seizes$5,000
Timing belt with water pump and tensioner - the single most important service item on the car$3,500

Similar cars, and what they cost to run

Evidence behind this valueThin · 1 recorded sale
Carried value
$70,000
Historical price
2016 · $51,8002026 · $70,000
Thin
At least one recorded transaction plus a source. Direction is sound, the exact level less so.
One dated result and one orphan

Shannons sold a 1988 928 S4 coupe for $56,000 in the Spring Online auction closing 18 November 2020, the only dated Australian figure for this model. The other number in circulation, $21,250, comes from Shannons' Similar Vehicle Sales panel on an archived 1989 S4 lot from the 2019 Sydney Autumn Classic sale. It is real published money, it is not that lot's result, and it carries no date and no odometer. Shannons left the auction business in November 2023 and the archive was stripped, so it cannot now be traced. Two figures nearly three to one apart, one of them unattributable, is the entire local record.

Read the rest of the evidence notes (3 more)
Transmission sets the price, not condition

Manual is worth 50 to 80 per cent over automatic, the largest transmission premium in this tranche, and an estimated 35 to 50 per cent of the current Australian pool is cheap British and Japanese automatics landed in the 2010s. That is how one model runs from $16,000 to $135,000. An Australian-delivered manual, from an estimated 100 to 200 S4s sold new here, is a different asset from the car that usually turns up.

The belt is the second variable and it is binary

A snapped cam belt writes the engine off, the repair is $35,000, and that exceeds the value of most survivors outright.

Australia has sold 928s since February 1978,

When the first cars landed at about $53,000, between the Mercedes-Benz 450SLC and the Jaguar XJ-S V12. No S4-era Australian list price was found, so none is carried.

This page prices the model.
The report prices the car in the advertisement.

Send the link. A person reads the advertisement and its photographs and sends back what that Porsche 928 S4 is worth, what to offer and when to walk away, with five years of costs at the distance you drive.

Read a real listing report

The evidence on this model is thin and the report says so on its cover. Read a complete one on a real car first. Seventeen sections, no account, nothing to pay.

This model, today$70,000
Half of sales are further out than$7,825
The report$249
31×
the price of the report: what half of real sales of this model sit further from this page's number than, on this car
Watch this model
Told when the next one is called.

One line of email when this desk publishes a call on a Porsche 928 S4, or records a new Australian sale of one. Nothing else, no schedule, and on a quiet model you may hear nothing for months, which is itself worth knowing about a car you are chasing.

Free. One address, one model, and no account.
928 for sale?Priced by a person, $249