Funnels

Which funnel fits which job?

The right choice depends on where you are pouring, not just what you are pouring. Here is the quickest route to the correct funnel:

• Adding a petrol additive to a car with an anti-siphon fuel cap: the Petrol Tank Funnel (Also for Anti-Siphon Valve) has a narrow, shaped spout that passes through the anti-siphon valve without forcing it, which a standard funnel cannot do.
• Adding a diesel additive or topping up from a jerrycan on a diesel car with an anti-siphon valve: the Diesel Tank Funnel (Also for Anti-Siphon Valve) is the correct fit for the same reason, matched to diesel system use.
• Topping up engine oil, coolant, screen wash, or working through several fluids in one session: the 4-Piece Funnel Set gives you multiple sizes in one purchase, so the wider funnels handle thicker fluids like engine oil and the narrower ones fit smaller reservoir openings.

The fuel funnels are the better fit for tank additive jobs specifically. The set covers everything else in a typical maintenance session.

Can I use the same funnel for oil and coolant?

Using the same funnel for different fluids without cleaning it in between risks introducing contamination. Oil residue carried into the cooling system can affect heat transfer and damage seals over time. AdBlue is even more sensitive: it is a urea solution that can be compromised by even small traces of oil, fuel, or dirt, which can damage the SCR system. A household or kitchen funnel adds a further problem, because soft plastics not rated for automotive fluids can swell, degrade, or release particles into the fluid.

• Do clean and dry the funnel thoroughly between different fluids.
• Do keep a dedicated funnel for AdBlue if you refill it regularly, one that has only ever contacted AdBlue.
• Do not reuse a funnel across oil, coolant, fuel, or AdBlue without cleaning it first.
• Do not use a household or kitchen funnel for automotive fluids.

For brake fluid, use a dedicated clean funnel and keep it separate. Whether brake fluid work is appropriate as a DIY job at all is a separate question; consult a garage or a dedicated guide before attempting it.

What does a funnel actually do for your car?

A funnel is a pouring tool. It makes the job cleaner and reduces the chance of introducing contamination. Everything else, choosing the right fluid, identifying a leak, reading a warning light, is outside its scope.

How to use a funnel without making a mess

1. Choose the funnel sized for your filler opening. Check that it sits securely before you pour anything. The fuel funnels are sized for tank necks; for oil and coolant, select the appropriate size from the set.
2. Make sure the funnel is clean and dry. Any residue from a previous fluid is a contamination risk.
3. Seat the funnel securely in the opening. Rest it in or insert it so it will not shift while you pour.
4. Pour steadily and not too fast, especially with thicker fluids like engine oil, to avoid overflow and air-lock glugging.
5. Remove the funnel before the fluid reaches the top of the opening.
6. Wipe the funnel and the area around the filler immediately, then store the funnel clean.

If you spill a significant amount in the engine bay, wipe it up before starting the engine. Oil on hot engine parts causes smoke and smell, and coolant on belts or electrical components can cause damage. If you are unsure where the fluid went, have a garage check before driving.

When should you stop topping up and go to a garage?

• You are topping up engine oil more than once between service intervals.
• You are repeatedly having to top up coolant.
• You cannot identify which fluid or specification your car requires.
• You suspect a leak: spots on the driveway, an unusual smell, or a warning light.
• The AdBlue warning light stays on after refilling. AdBlue system faults, sensor issues, and SCR problems need diagnosis, not more fluid.
• The cooling system requires bleeding or pressurising to work correctly.

For a straightforward top-up where you know the correct fluid and the level is simply low, a clean funnel and the right product are all the job needs. If you are uncertain about any of those conditions, a garage is the right first call.

Not sure whether you need a fuel-specific funnel or whether the set will cover your job? If you are adding a tank additive to a modern car with an anti-siphon fuel cap, the dedicated fuel funnel is the right answer. For everything else in the engine bay, the set covers it.