It is no longer safe to mention the cost of petrol and diesel in a public place.

The vapours of fury from everyone in earshot are enough to send even the most placid vicar into apoplexy.

For many households, putting fuel in the tank has become one of their biggest bills, costing thousands a year - up there with mortgage or rent, and gas and electricity.

The majority is tax that you can do little about. Of course the no-brainer is sell the car, switch to a more efficient model or drive less. I am assuming you know all that, so my aim is to show you the key steps to cutting your bills on those must-do journeys.

There are five main routes to reducing the cost.

Think of your accelerator as a money pump. The harder you press, the more morney is turned into fuel

Route 1. Make your car more efficient

Several easy things improve fuel efficiency. Each is worth a per cent or two, but combined, they can make a huge difference.

● Check your tyres are correctly inflated; lower tyre pressure increases drag (or wind resistance).

● Get rid of the junk in your trunk. Excess weight in the boot means the car has to work a lot harder to accelerate.

● Remove roof racks if you are not using them. Even unused roof racks add wind resistance, making the engine work harder.

● Turn air-conditioning off; up to eight per cent of your fuel bill goes on it. I am not saying that you should sit in your car and boil like a lobster, but be aware of the cost.

● Do not fill up your tank to full. Formula One racing drivers go faster towards the end of the race as there is less petrol in the car, so less weight. Be a petrol-saving nerd by only topping up to three-quarters full. Though only if your cheapest petrol station is on a regular route, so you won't need extra trips to fill up.

Route 2. Drive efficiently

This is the biggest saving, though people find it hard to visualise as it takes a while for the saving to hit. While cutting maximum speed helps, the real focus should be on being less aggressive in stops and starts, especially in urban areas.

Think of your accelerator as a money pump. The harder you press, the more money is turned into fuel. Your brake is a money burner: pressing it converts the speed you paid to put into the car into heat.

Perfect driving would be gradually accelerating to the maximum speed, and not breaking to slow down, just allowing the car to coast to a stop. Sounds great, but it would probably make you slightly annoying on the road.

This is more about not burning away from traffic lights only to slam on the brake at the next one 200 yards later. Accelerate gradually, keeping your distance from the car ahead so you have room to slow slowly. Many who try it get 10-30 per cent more out of a tank. If you fill up £50 a week, that is easily £500 a year.

Route 3. Find the cheapest petrol and diesel

The gaps between forecourts are widening. The UK's cheapest petrol is now £1.36 a litre and the priciest is £1.50. Enter a postcode at petrolprices.com and it shows you the cheapest petrol in the vicinity.

Keep an eye out for petrol discount vouchers at supermarkets; these can cut costs by another 5-10 pence a litre.

Route 4. Get cashback on all fuel

Petrol or diesel is the biggest regular expenditure many people make by plastic or cash, meaning opportunities to boost savings.

The key is to use a cashback credit card. Let me make this plain for you: only do this if you are debt-free and will set up a direct debit to clear the balance in full every month to avoid interest or it is pointless.

For long term cashback, MBNA American Express pays 1.5 per cent cashback on all petrol and supermarket spending and 0.75 per cent elsewhere. Spend £5,000 a year on food and fuel, and that is £75 back (it is 18.9 per cent APR if you do not repay in full).

Other cashback cards pay up to five per cent cashback, but for a shorter time. See the full list at www.moneysavingexpert.com/cashback

Route 5. Share your driving with others

Have a word with work colleagues or parents at your children's school to see if they fancy sharing the driving. Web-based versions widen the net; you can check sites such as liftshare.com and rideshare.co.uk but make sure you are vigilant and stay safe if you are meeting someone via this method.

If you are carrying passengers and it is not a commercial arrangement, this should not affect your insurance.