Oil Service Cost Calculator

What's actually being compared

Both totals use the same oil capacity and service interval, since those are set by the engine and the manufacturer's schedule, not by who does the work (work out the engine's own numbers with the displacement & compression calculator). What differs is what each route pays for: DIY buys retail oil and a filter and may face a small disposal fee at a recycling centre, while a garage quote bundles trade-priced parts (sometimes cheaper, sometimes marked up) with labour. Type in your own quote or receipt to make the comparison exact rather than typical.

Why garage oil prices vary so much

Garages buy oil in bulk at trade rates that can undercut retail, but many also apply a markup on parts to cover storage, disposal and warranty risk on the oil grade fitted. That's why two garages quoting the same car can differ by £20 or more on parts alone, before labour is even considered. Entering the actual quoted parts price, not a guess, is what makes this comparison worth trusting.

Per-1000-miles is the fairer number

A single service cost doesn't account for how far apart services fall. A car serviced every 10,000 miles and one serviced every 6,000 miles can have very different running costs even with an identical invoice, because the cheaper-looking service happens more often. Dividing by the interval turns both into a comparable running cost, useful when weighing up a longer-life oil or an extended-interval service plan.

What this tool doesn't check

It doesn't verify that the oil capacity or grade entered is correct for your engine, that's a handbook figure, not a calculation. It also doesn't account for anything found and quoted separately during a service, such as a worn sump washer needing replacement, brake fluid due, or an air filter change, all of which are genuine costs but not part of the oil change itself.