Diesel rises by 5.4% and petrol by 4.8% in September 2026, CSO finds

The price of diesel rose by 5.4% and petrol by 4.8% in September 2026, and up by 22% and 14% respectively since September last year.

The figures were released by the Central Statistics Office (CSO), and this is the largest annual increase in petrol prices since May 2024.

When it came to the price of home heating oil, it rose by 7.2% in the month between August 2026 and September 2026, up by 58.6% in the 12 months to September 2026.

The CSO say that in September 2026, Petrol was at its highest price since August 2022, with diesel was at its highest level since April 2026, which was the highest level seen since July 2022.

Anthony Dawson, Statistician in the Prices Division of the CSO, said: “This Insight Series release focuses on the price developments of Diesel, Petrol, and Home Heating Oil in Ireland since 2019. This is a more detailed look at data from the Consumer Price Index (CPI) for September 2026, which has also been published today. In the month of September 2026, we saw significant price movements for Fuel and Home Heating Oil.

“Diesel and Petrol increased by 5.4% and 4.8%, respectively, in September 2026, while Home Heating Oil prices rose by 7.2% when compared with prices in August 2026. Overall, the CPI increased by 0.2% in the same period.

“When comparing September 2026 with September 2025, Diesel rose by 22%, Petrol by 14%, and Home Heating Oil prices were up by 58.6%.

“Overall, the CPI increased by 4.1% in the 12 months to September 2026. In terms of percentage point (pp) contributions, Home Heating Oil contributed 0.45pp towards the overall inflation rate in September 2026. Diesel contributed 0.34pp towards inflation, while Petrol contributed 0.26pp. In August 2026, Home Heating Oil contributed 0.35pp towards inflation, Diesel 0.23pp and Petrol 0.16pp.

“When we look at the price indices which show price trends over time, in September 2026 the price of Diesel was at its highest level since April 2026, which was the highest level seen since July 2022, while the price of Petrol was at its highest level since August 2022. Home Heating Oil was at its highest level since April 2026, which was the highest price level since the CSO started publishing detailed sub-indices almost 30 years ago in November 1996.

“Users should note that prices for September were collected during the period 07 September to 15 September inclusive. Prices may have increased or decreased between then and the end of September. Further information on the methodology for Fuel and Home Heating Oil can be found below under the Methodology section”