The decision by the big supermarket chains to shave a penny or two off their fuel prices is little comfort to motorists, who pay one-third more to fill up than they did five years ago.

But there are ways to make significant savings when it comes to running a vehicle.

According to British Car Auctions, despite the move by Asda, Morrisons, Sainsbury's and Tesco, the price of fuel remains drivers' biggest financial worry, followed by road tax and insurance.

The typical cost of a litre of unleaded petrol had risen from 106p in March 2008 to just under 140p by last month, taking the bill to replenish a 50-litre tank from £53 to almost £70.

As a result, many people are driving less. Recent research by Saga found more than one-third of Scots over-50s have tried to minimise their motoring costs.

The insurer says its customers, who all fall into this age range, have typically slashed their mileage by one-fifth since the start of the credit crunch, opting instead to walk, cycle, use public transport or shop online when possible.

As well as reducing petrol bills and vehicle wear and tear, this can lead to lower insurance premiums, as fewer miles means less risk of being involved in an accident.

Roger Ramsden, chief executive of Saga Services, said: "Older people are feeling the pinch and cutting back on driving, but everyone could save money and make the most of their journeys."

However, many under-50s, particularly those who rely on their car for a daily commute, find it difficult to reduce the time they spend at the wheel. But there are other ways to shrink costs.

To find the cheapest petrol or diesel in the area, register with free website Petrolprices.com and compare suppliers within your preferred radius before going to fill up. Road tax bands are based on carbon dioxide emissions, so choosing a greener model next time you replace your vehicle will help financially as well as benefiting the environment.

Over the past three years, the AA's insurance premium index has recorded some of the biggest price increases ever.

Simon Douglas, the motoring organisation's director of insurance, said: "Sharp hikes in personal injury claims, fraud and uninsured drivers, to say nothing of last year's gender directive and changing regulations, have all helped to pile on the pounds."

But it is still possible to cut the cost of insurance without skimping on cover.

While the AA's Shoparound summary, which collates the cheapest quotes from brokers, insurers and comparison sites, found the average for third party, fire and theft rose by almost 1% over the past 12 months and 2% between January and April this year, premiums for comprehensive cover fell by 4.1% over the year and 1.4% in the last three months.

Insurers tend to reserve their best prices for new customers, though, so when it comes to renewal time, do not simply sign up for another year with your existing provider, no matter how cheap their offer last time.

Get quotes from at least two comparison sites, as they do not all cover the same providers, and check with big players Aviva and Direct Line, as they don't appear on third-party sites.

But, no matter how temptingly low the prices you find, do not buy without making sure the cover is adequate for your needs. Budget insurance that does not pay out when something goes wrong is a complete waste of money.

Increasing the voluntary excess or opting for third party, fire and theft cover instead of fully comprehensive can make a significant difference, but if an accident leads to a large repair bill, it could be a false economy.

Almost half of motorists spread their costs by paying monthly. However, most insurers charge extra for this. Moneysupermarket.com calculates the industry earns £1.6 billion a year – or £89 per driver – in premium interest.

Peter Harrison, the comparison site's car insurance expert, said: "A handful of insurers refrain from doing so, but more often than not an additional cost will be applied if you opt for paying monthly rather than annually. Cash-strapped motorists could consider other financially savvy ways to spread the cost of their premium, such as using a 0% purchase credit card."

It may also save money in the long run to pay a bit extra initially to protect your no-claims discount. According to Moneysupermarket, the average charge for this is just £23.

The site says a motorist with five years' unprotected NCD who makes a claim can expect to see their premium rise from £322 to £417, an increase of £95, or 30%. However, someone with five years' protected NCD can expect to pay only 8% or £28 more, taking their typical premium from £345 to £373.

Mr Harrison said: "Building up your no-claims discount over a number of years can be a valuable commodity and can help reduce the cost of your premiums. With premiums on average rising by almost one-third if you make a claim, paying extra to protect your policy against this hike might be worthwhile."