Across Wales on One Tank

Rhayader is where a driver crossing Wales in 1971 found out whether the map or the tank was going to win. The AA Motoring Trust’s historical price series puts the average British pump price that year at 34.25 new pence a gallon. The entry immediately above it, for 1970, reads 80.00, because the series breaks in two at 1971 and everything above the break is counted in old pence, 240 to the pound.

The break is Decimal Day. The Decimal Currency Act 1969 defines “the appointed day” as 15 February 1971, and the same Act turned 11, 12 and 13 February into non-business days so that the banks could convert their ledgers without customers in the room. At 2.4 old pence to the new penny, 34.25p a gallon was 82.2 old pence, which is six shillings and tenpence. The AA’s table carries a tax column alongside the price, and for 1971 it reads 65.69 per cent. Do that multiplication and the tax comes to 22.5p a gallon, which in the money most people still counted in was exactly four shillings and sixpence.

The Road That Was Not Yet The A470

Cardiff to Llandudno is one number today, and 185.1 miles long. It was not one number then. The Roader’s Digest, the SABRE road archive, records that the original 1922–23 A470 ran only from Cardiff Docks to the A40 at Brecon, and that the designation was pushed north to Glan Conwy in 1972. Everything beyond Brecon carried something else. The archive lists eleven former numbers along the modern route, among them the A438, the A479, the A44, the A492, the A489, the A487 and the A496. A driver leaving Rhayader for the north that autumn turned onto the A44 and stayed with it as far as Llangurig, which is precisely what the A470 still does today, sharing tarmac with the older number and taking priority at the signs.

The southern end was a building site. The archive’s list of opening dates gives the Whitchurch bypass in Cardiff on 6 October 1959 and then nothing at all until 3 December 1971, when the dual carriageway between Tongwynlais and Nantgarw opened, two months after the month we are looking at. Nantgarw to Upper Boat followed on 29 June 1973, Upper Boat to Abercynon on 18 December of the same year. Brecon was not bypassed until 28 August 1980, Dolgellau until 13 April 1981, Llanidloes until 25 February 1991. In October 1971 the road went through all of them, at whatever speed the high street would allow.

Which was, legally, seventy. The 70 miles per hour Speed Limit (Wales) Order 1967 was made on 13 July 1967 by Cledwyn Hughes, then Secretary of State for Wales, and came into operation on 4 September. Its business was housekeeping: the temporary 70 mph maximum imposed on all Welsh roads other than motorways was due to expire at midnight at the end of Sunday 3 September 1967, and this Order continued it, in the drafting of the day, indefinitely. There was no separate, lower national limit for single carriageways to sit beneath it. The maximum on the unbypassed main street of every town between Cardiff and the coast was seventy miles an hour.

The Arithmetic Of One Tank

Put a Morris Marina 1.3 on that road, a car new to British showrooms in 1971. The period technical data tables give it an 11.5 imperial gallon tank and a fuel consumption figure of 34 miles to the gallon. Those two numbers multiply to 391 miles of theoretical range, which is Cardiff to Llandudno with two hundred miles in hand, on paper. The 185.1 miles need 5.44 gallons. At 34.25p that is £1.86, or, in the coins still in most pockets that October, one pound seventeen shillings and threepence ha’penny. Filling the tank from empty cost £3.94, which is £3 18s 9d. The 34 mpg is a period-quoted figure rather than a measured test, and it should be read as an advertisement for arithmetic rather than for the Marina.

1971 34.25p

1972 35.25p

1973 38.70p

1974 49.60p

1975 73.20p

The series more than doubles in four years. 1971 sits at the bottom of it.

Source: AA Motoring Trust, 2005

What The Road Runs Past

West of Rhayader the B4518 climbs into the Elan Valley, and the reason it is there is Birmingham. The Elan Valley Trust’s timeline dates the Birmingham Corporation Water Act to 1892, signed by Queen Victoria that July. Work on the dams began the following year and work on the aqueduct in 1896. King Edward VII and Queen Alexandra opened the dams on 21 July 1904, and the first continuous flow of water through the aqueduct followed a week later, on 28 July. Queen Elizabeth II opened the Claerwen dam on 23 October 1952, one of her first duties as monarch. A motorist pulling over for the view in 1971 was admiring English drinking water.

Further north, the same logic produced something Wales has not forgiven. The Royal Commission on the Ancient and Historical Monuments of Wales records Llyn Celyn as built between 1960 and 1965, part of the Bala Lake Scheme in the River Dee catchment, to provide a constant supply of water for the City of Liverpool. Some 320 hectares went under 81 million cubic metres of water. The village of Capel Celyn and twelve farms were drowned. The Commission’s own record calls it a great controversy at the time which still lingers today, and sends the reader to the Cofiwch Dryweryn wall near Aberystwyth. Six years on, in 1971, it was recent news rather than history, and any account of driving through mid Wales that files the reservoirs under scenery is not describing the place.

The Same Journey, Now

Measure	1971	2026
Average pump price, petrol	34.25p a gallon (7.5p a litre)	152.29p a litre
Tax within that price	22.5p a gallon, or 4s 6d	78.3p a litre (duty plus VAT)
Tax as a share of the pump price	65.7%	51.4%
Fuel for 185.1 miles at 34 mpg	£1.86, or £1 17s 3½d	£37.69
Households with no car, Great Britain	48%	22% (2024)

Source: AA Motoring Trust; Department for Energy Security and Net Zero; Bank of England; Department for Transport, 1971–2026

The Bank of England’s inflation calculator, whose index runs to 2024, puts £1 of 1971 money at £12.25. On that basis the 1971 gallon cost £4.19 in modern terms, or about 92p a litre. The Department for Energy Security and Net Zero’s weekly series put the UK average for unleaded at 152.29p a litre on 20 July 2026. Petrol is roughly 65 per cent dearer in real terms than it was in the year Britain went decimal, and the £1.86 that took a Marina from Cardiff to Llandudno is £22.84 in 2024 money against £37.69 at today’s pump.

The duty is the surprise. Convert 1971’s 22.5p a gallon into pence per litre and it comes to 4.9p; put that through the same index and it is about 61p a litre in 2024 money. The duty rate on the same weekly series is 52.95p. Fuel duty is lower in real terms today than it was then, and tax’s share of the pump price has fallen from 65.69 per cent to roughly 51 per cent even with VAT stacked on top. What has risen is the price of the fuel itself.

The other figure worth carrying out of 1971 is the Department for Transport’s. Forty-eight per cent of British households had no car at all that year, against 22 per cent in 2024, so the tank arithmetic was academic for half the country. What the Marina’s owner had, and his neighbours did not, was the ability to leave Cardiff after breakfast and see the sea at Llandudno before dark, for one pound, seventeen shillings and threepence ha’penny, on a road that would not become one road until the following year.