Is premium diesel worth it?
What premium diesel is, what the brands claim for it, and the economy gain it would need to pay its way.
By Forecourt Prices Published Updated
Standard and premium diesel prices across the UK
UK average
UK average
premium diesel dearer, per litre
for premium diesel, against 6,341 for standard diesel
Today's UK averages come from 6,341 forecourts with a standard diesel price and 2,205 with a premium diesel price in our price data. We update it every 15 minutes. See how we work them out.
Updated 6:47am on 2 November.
The short answer
Today premium diesel averages 217.4p a litre across UK forecourts, 19.0p dearer than standard diesel at 198.4p. On a 55-litre fill that is £10.45 more. Over 8,000 miles a year at 48.4 mpg it adds up to about £145, or about £215 over 12,000 miles.
What premium diesel is
Standard diesel in Great Britain can contain up to 7% biodiesel. The rules also set a minimum cetane number of 51[1].
At the pump it is labelled B7. The B means diesel blended with biodiesel, and the 7 is the most it can contain, in per cent[2].
Premium diesel is diesel too, with more of the brand's own additives, mostly detergents meant to keep the engine clean[3][4].
None of the brand pages below gives a cetane number for its premium diesel. Our station pages list it as super diesel.
Other diesels get a square label under the same rules. It shows B and the most biodiesel they can contain, or XTL for paraffinic diesel[2]. Our station pages list B10 and HVO separately where a forecourt reports them.
What the makers claim
Esso says Esso Synergy Supreme+ Diesel has double the detergent additive of its regular diesel. According to Esso, this helps the fuel burn more efficiently, for better fuel economy[3].
BP says BP Ultimate Diesel removes dirt from inside the engine and helps stop it coming back. It claims up to 375 more miles a year for a driver doing 6,400 miles, from tests of engines dirty and then cleaned. BP also says ongoing use helps restore engine power and gives a smooth drive[5].
Shell says Shell V-Power Diesel has 60% more cleaning and protection molecules than its FuelSave Diesel. Shell also says industry and Shell tests have shown better fuel economy, though it gives no guarantee[6].
Texaco says regular use of Texaco Supreme Diesel can help improve acceleration and fuel economy, cut exhaust emissions and deliver smooth performance[7].
JET says its ULTRA fuels, JET ULTRA Premium Diesel among them, have more detergent to help remove deposits. It adds that they have more anti-corrosion additive to protect engine parts[4].
We haven't tested any of these claims.
GOV.UK gives a fuel economy figure for E10 petrol[8]. We have found no government figure for premium diesel, so we make no economy claim of our own.
If you want to try premium diesel, 2,205 UK forecourts have a premium diesel price from the last 30 days. That compares with 6,341 for standard diesel. Not every forecourt sells it, so check the station page before you set off.
Is premium diesel worth the extra?
Premium diesel pays for itself only if it cuts what you spend per mile. To do that, it has to improve your fuel economy by at least the same percentage as it adds to the price.
These figures are illustrations, not test results. Take today's standard diesel average of 198.4p. If premium diesel gave 1% better fuel economy, it would pay its way at up to 2.0p a litre more. At 2% that rises to 4.0p, and at 3% to 6.0p.
Today it costs 19.0p more. To pay for that, premium diesel would need to improve your fuel economy by at least 10%.
How the gap has moved
Average standard diesel (B7) and premium diesel prices across UK forecourts each day since 7 February 2026.
- On 1 November, premium diesel cost 19.0p a litre more than standard diesel.
- The gap is down 0.5p over 7 days, up 0.4p over 30 days and up 0.1p over 90 days.
- Since 7 February 2026 the widest it has been is 21.5p, on 8 February, and the narrowest 15.2p, on 4 April.
Figures to 1 November 2026.
Daily UK averages from our price data.
Where premium diesel costs least extra
Each brand's average standard diesel and premium diesel price at its own forecourts, not counting motorway services, smallest gap first.
Brand averages from our price data, from each brand's forecourts away from motorway services.
| Brand | Standard diesel | Premium diesel | Gap |
|---|---|---|---|
| Circle K, mostly from older prices | 190.7p | 195.8p | +5.1p |
| Maxol, mostly from older prices | 190.9p | 196.1p | +5.2p |
| Go, mostly from older prices | 187.6p | 194.7p | +7.1p |
| Essar, mostly from older prices | 196.9p | 204.3p | +7.4p |
| Morrisons, mostly from older prices | 196.5p | 206.4p | +9.9p |
| Co-op, mostly from older prices | 197.2p | 211.2p | +14.0p |
| Texaco, mostly from older prices | 196.8p | 212.0p | +15.2p |
| TotalEnergies, mostly from older prices | 197.7p | 214.4p | +16.7p |
| Gulf, mostly from older prices | 199.2p | 216.0p | +16.8p |
| BP, mostly from older prices | 199.6p | 218.2p | +18.6p |
| EG On The Move, mostly from older prices | 197.8p | 216.9p | +19.1p |
| Shell, mostly from older prices | 200.3p | 222.8p | +22.5p |
Figures marked † are mostly from prices over 3 days old.
Common questions about premium diesel
Does premium diesel improve fuel economy?
Esso, Shell and Texaco say it can[3][6][7]. BP claims up to 375 more miles a year[5]. None gives a figure that holds for every car, and we haven't tested them. Higher up the page we work out the gain it would need to pay its way.
How much more does premium diesel cost?
Today premium diesel averages 217.4p a litre across UK forecourts, 19.0p a litre more than standard diesel at 198.4p. On a 55-litre fill that is £10.45 more.
What is supreme diesel?
It is premium diesel under another name. Esso sells Esso Synergy Supreme+ Diesel and Texaco sells Texaco Supreme Diesel[3][7]. Esso says Esso Synergy Supreme+ Diesel has double the detergent additive of its regular diesel[3]. Texaco says regular use of Texaco Supreme Diesel can help improve acceleration and fuel economy[7]. Compare each brand's premium diesel.
Does my car need premium diesel?
Check your handbook for the fuel your car needs. Standard diesel has to meet the same rules as premium diesel[1]. The case for premium rests on the brands' own claims, set out above.
Can you mix premium and standard diesel?
Both are diesel, and both have to meet the same rules[1]. Premium diesel is diesel with more of the brand's own additives[3]. We haven't found a brand page that warns against it.
Is premium diesel better for my DPF?
None of the brand pages we checked says its premium diesel helps a diesel particulate filter (DPF). BP makes no DPF claim for BP Ultimate Diesel[5]. Shell says its premium diesel helps protect the exhaust gas recirculation (EGR) system from deposits[6]. We haven't tested this.
Is premium diesel better for older or high-mileage cars?
We hold no figures on engine age or mileage, so we can't say. None of the brand pages we checked says older engines gain more. Shell and JET say results vary with a vehicle's age and condition[6][4].
Does premium diesel last longer?
None of the brand pages we checked gives a shelf life for its premium diesel. Where a brand talks about lasting longer, it means the engine. Shell says Shell V-Power Diesel is for a longer lasting engine[6].
Can I switch back to standard diesel?
Yes. Standard and premium diesel have to meet the same rules for diesel[1]. The brands do say their cleaning benefits build up with regular use. BP says BP Ultimate Diesel works best with ongoing use[5].
What is BP Ultimate Diesel?
It is BP's premium diesel. BP says it removes dirt from inside the engine and helps stop it coming back[5]. We haven't tested this.
Is premium diesel the same as HVO?
No. HVO is hydrotreated vegetable oil, a diesel-quality fuel made from biomass[10]. Premium diesel is diesel with up to 7% biodiesel[1], plus the brand's extra additives. Forecourts report HVO as a fuel of its own, and our station pages list it separately.
What is Costco premium diesel?
It is the one diesel Costco sells, at forecourts open to Costco members only[9]. Costco's standard diesel (B7) averages 189.5p a litre at 20 forecourts. That is 8.5p less than the UK standard diesel average of 198.0p away from motorway services. It has no usable premium diesel average in our figures. Most of the prices behind the Costco standard diesel average are more than 3 days old. Costco's standard diesel (B7) is 33.3p less than Shell V-Power Diesel and 28.7p less than BP Ultimate Diesel, on each brand's average.
Are there problems with Costco diesel?
We hold no data on fuel faults at Costco or any other brand, so we can't say.
Where is premium diesel cheapest?
The table above has each brand's average premium diesel price and how much more it costs than its standard diesel. To find the cheapest premium diesel near you, search by postcode or town and choose Super Diesel. Search for premium diesel near you.
Sources and method
- legislation.gov.uk: The Motor Fuel (Composition and Content) and the Biofuel (Labelling) (Amendment) (No. 2) Regulations 2021, regulation 11, checked 13 October 2026.
- legislation.gov.uk: The Alternative Fuel Labelling and Greenhouse Gas Emissions (Miscellaneous Amendments) Regulations 2019, Schedule 1, checked 13 October 2026.
- Esso UK: Synergy Fuels, checked 13 October 2026.
- JET: JET ULTRA, checked 13 October 2026.
- bp UK: bp Ultimate Diesel with ACTIVE technology, checked 13 October 2026.
- Shell UK: V-Power diesel fuel, checked 13 October 2026.
- Texaco UK: Our Motor Fuels, checked 13 October 2026.
- GOV.UK: E10 petrol explained, Fuel economy, checked 13 October 2026.
- Costco UK: Costco Fuel - Your questions answered by our fuel experts, checked 13 October 2026.
- GOV.UK: Using rebated fuels in vehicles and machines (Excise Notice 75), What is rebated fuel, checked 13 October 2026.
Our figures: each UK average is over every forecourt's latest price reported in the last 30 days, leaving out prices far from what the rest of the UK charges. The brand figures leave out motorway services too. How we work out the figures