Expert answer

Hi Finian,

Possibly, but it depends entirely on the car and how you're driving it. If you're talking about a small diesel-engined hatchback, then yes, there's quite possibly a problem if you're only getting 19mpg on average. Even driven for only short hops around town, most would manage at least 35mpg on average. Certainly worth a visit to the dealer to at least have it looked at.

That said, the single biggest influence on fuel consumption is driving style. Have you changed the way you drive, or your regular route lately? Are you spending a lot of time idling at traffic lights where you previously weren't? It all adds up...

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Hi Kieran,

Not massive. There's a tiny 1mpg gap between them in terms of fuel economy (the Toyota gets 59mpg, the Ford 60mpg), but in everyday driving , they'll probably work out pretty much the same.

Overall, the Toyota will probably be slightly more reliable, and the Ford slightly cheaper to service and repair if anything does go wrong. The Toyota will probably be a little cheaper to insure too, and its road tax will be slightly lower.

On balance then, the Toyota is likely to be fractionally cheaper to run, but there's precious little in it.

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Hi Martina,

There are many possible reasons for this drop off in your fuel economy. Start with the easy things - you'd be surprised how important they are.

1 - Are you carrying extra weight in the car now than you were before? Golf clubs (or bricks!) in the boot? It can have a large effect.

2 - Have you fitted a roof rack/box? Again, can have a massive effect.

3 - Check the air pressure of your tyres. This is very very important. Underinflated tyres cause extra drag, requiring more fuel. Don't over-inflate either though, as that could lead to a blow-out. Follow guidelines for the car/tyre.

4 - It's winter so you're most likely using the lights, heater and demister a lot more. Those all use fuel. In particular, make sure you turn off the rear window demister when it's not needed - it uses a lot of energy.

All the above you can do for yourself, so do and then see if things have improved. After that we would suggest that you have your car serviced if it has been a while. The air filter and/or fuel filter could be clogged and it's a good time to hook the car up to a diagnostics machine to see if there are any error codes indicating other issues.

Let us know how you get on

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Hi John,

Yes, I'd say you're onto a good one there. Obviously, a well used 14-year old Astra isn't going to come with a bundle of trade-in value attached, so I think the price looks pretty fair for the Octavia, especially given the low mileage. Honestly - we see press cars with higher miles than that!

As for the petrol/diesel side of things, I think you'll be fine in the 1.2 TSI. At 11,000 miles a year you're well within the bracket to keep burning petrol rather than switching to more expensive diesel (more expensive to buy the car, not the fuel of course) and the good news is that the 1.2 TSI engine is exceptionally frugal. In fact, I once drove one for 200km before I realised that it wasn't diesel, so slow moving was the fuel gauge. In my defence, it was late and I was tired...

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Hi Rasti,

I'd say that kind of mileage puts you just over the tipping point for diesel, but if you must insist on petrol then go for the 1.6 - that 1.4 is so underpowered that you have to work it hard to get any performance out of it, and that really hurts the fuel consumption. As for buying privately, just keep your wits about you. The Octavia is a solidly reliable and well made car, which lowers the risk, but don't accept anything without immaculate paperwork and a proper, fully-stamped service history. None of this my-brother's-a-mechanic-and-he-looked-after-it rubbish. Worth getting a history check (from the likes of Cartell.ie) and maybe an AA inspection too. Be especially wary of cars with outstanding finance still owing on them.

Expert answer

Hi Martin,

There's little else worse than getting unexpectedly bad car repair news, and we all know how it feels. Now, as you point out, you have, essentially, two options here. One is to trade in the car without the work done and get something new. Now, that's a very tempting option and one that would at least put you back under a warranty and give you reasonably predictable monthly repayments etc, all of which is good news.

The thing is though that your Mondeo is only six years old and to my mind there should be an awful lot more left in it. I would be tempted, especially as you've also just upgraded your wife's car, to take the €3k on the chin and keep yours going for a while yet. You're at a point in its life where the value isn't going to sink all that much more anyway, so keeping it an extra year or 18 months isn't going to have an enormous impact - with the age and mileage already on it, it's going to be at the lower end of the value scale anyway.

One thing worth considering: rust doesn't happen overnight. If, as you say, this car has always been serviced to schedule with the same dealer, ask them why the problem wasn't flagged up sooner. You may be able to use that as a bit of a stick to beat the price down a touch.

Let us know how you get on

Expert answer

Hi Philip,

It varies from station to station and supplier to supplier, but the standard for all Irish fuel is E5, which allows for (but doesn't specify) a five per cent mix of bio-derived ethanol in petrol. Ask at your local station to be certain though.

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Hi Jon,

I'm afraid this sort of thing is nigh on impossible to diagnose from afar as there are so many factors at work. Here are a few things to look at, but really, you need a mechanic to take a look:

- Hook it up to a diagnostic machine and get any error codes - that could save time

- Perhaps the glo plugs aren't working - they'd be needed in this cold weather (if it's diesel)

- Maybe the fuel tank pump isn't working. Turn the ignition on and you should hear a buzz from under the rear seats

- Is there sufficient fuel in the tank?

Best of luck with it - let us know how you get on

Expert answer

Hi Ken,

It's difficult to know from afar, but there are several things that will affect this - assuming you're seeing a reduction in your car's economy:

1 - Tyre pressures need to be within specification

2 - Wheel alignment must be correct

3 - Perhaps the air filter and/or fuel filter is dirty and needs replacement

4 - Are you carrying extra weight in the boot?

5 - Is the rear window demister on permanently? 

Go through all of those things, starting with those that cost nothing to check and you should find savings. If not, then get the engine are car serviced and that might help. Perhaps a brake is binding.

Let us know how you get on

Expert answer

Hi Joe,

I presume you're asking this from a classic car point of view? The bad news is that pretty much all petrol sold in Ireland conforms to E5, or in other words has been blended with a five per cent mix of bio-source ethanol - alcohol derived from plants. The good news is that there's no evidence that running an older engine on E5 has any unpleasant effects. If the car has already been updated to accept unleaded petrol then you should be fine. The only issues arise when the car is left standing for a long time with the fuel sitting in the tank. Then the ethanol and petrol can separate, which can cause corrosion in the tank and/or fuel lines.