Expert answer

Hi John, 

The Atkinson engine is a type of engine invented by James Atkinson in 1882. The Atkinson Cycle is where the stroke of the piston can very in length across the four cycles in a four-stroke internal combustion engine. The length of the stroke during the power cycle is increased to promote efficiency, but because this comes at the expense of a shorter intake stroke there is some loss of power and therefore this engine design is best suited for use in hybrid systems where the electric motor can make up for some of the loss of power. 

In conventional four-cycle petrol engines, fuel enrichment is sometimes necessary to cool the exhaust gases, preventing degradation or destruction of the catalytic converters. In an Atkinson cycle engine, compression and expansion are not symmetrical, and the valves close late, delaying compression. This creates a high expansion ratio for less compression, reducing intake and exhaust energy losses and converting combustion energy to engine power more effectively. As a result, the exhaust temperature is lower than that of conventional engines.

The current model Toyota Prius Hybrid uses a 1.8-litre Atkinson Cycle engine. Adopting the Atkinson cycle and a cooled exhaust gas recirculation system brings significant gains in fuel efficiency and emissions reduction.

Prius 1.8-litre Atkinson Cycle engine

Because the intake valves close late in an Atkinson cycle engine, compression is delayed. This creates a high expansion ratio for less compression, reducing intake and exhaust energy losses and converting combustion energy to engine power more effectively. As a result the exhaust temperature is lower than that of conventional engines. Cooled Exhaust Gas Recirculation reintroduces the cooled gas into the intake system, further reducing engine operating temperatures.

Other models to use Atkinson Cycle engines include the Lexus CT200h, Lexus RX 450h, Mercedes S400 Blue Hybrid

Expert answer

Ray, do you know what? I am like you. I would always go for the older, more interesting car rather than the brand new snooze-box. I won't lie to you though, the Saab could be a pain if you compare it to something like an Avensis (sorry, I nodded off there). Look, a few things might end up going wrong, but it is a way cooler car than the ones that you mentioned. Repairs won't be too bad as most Opel dealers can cope with them pretty well. I'd say go for it, but don't expect it to be as trouble free as an Avensis.

Expert answer

Yes, these are excellent cars so I would say that you should have little in the way of trouble with them really. Obviously a diesel version might suit better, but if you are getting the petrol model at the right price and your mileage is low then this could be a decent purchase. 

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Hi Mark,

It is hard not to look past a BMW 520d Touring. There are a few nice ones around that fit your budget and to be honest this is where I would be looking. You might need one from a dealer if you intend to trade in. They are super cars and cheap to run too.

However, an outside choice as an estate is the Volvo V70. I personally love them as they are timeless and great for the dogs too. I have been drooling looking at this one in Cork all week and I reckon it would be a super buy - look at how low the mileage is!

Failing that, and if you aren't too worried about it being petrol, then a Subaru Outback is a marvellous car; this one has low mileage and is within your budget.

You might notice I didn't mention any Audis there. I figure you want a change, otherwise you wouldn't be asking us!

Best of luck with the change and make sure to tell us what you bought. You will find us on Twitter @completecar.

Expert answer

Hi Derek,

Glad you like the site. Let's hope we can live up to your expectations! We got a little bit of extra information from you and you told us that you are trading in a 2000 Mazda 323 five-door and that your budget is around €30,000-€32,000, which is plenty to work with.

Given your criteria, and the fact that you mention the Audi A5, then I've had a look at some of those. You mention petrol models and with your low mileage then you could quite easily run a petrol car, but given the fact that you are concerned about residuals then the diesels in the A5 would make a better choice. There is a lovely 2.7-litre TDI A5 in the classifieds and this is under €30,000. It would be a smashing buy and the fact that it has quite high mileage doesn't really mattter in your case. The 2.7 TDI version would hold its value better than a 2.0T petrol. 

At the other end of things you mention the Mazda6 - an odd contrast to the Audi but still a nice car nonetheless. You are unlikely to find a petrol-powered Mazda6 because Mazda really hasn't sold any in the last few years in Ireland. Plus, it wouldn't be a good use of money because it would be hard to sell on again a few years down the line. The diesel version is so much better anyway these days and you could have a demo 2011 model for well under €30,000. It is a nice car, but to be honest we can find you something a little more interesting. 

How about a Jaguar XF 2.7 D Luxury? What a super car, for €33,000. This is a marvellous example and fully loaded with kit. Another outside bet would be a 2008 Lexus GS 450h. We found a low mileage one that would be great around town and it is super fast. 

After all that, this is the car I think would suit you best. It is petrol, a 320i, but it is a hard-top convertible and it looks awesome. I don't know if you are a BMW fan but this could be a brilliant buy for you. 

Come back to us if we've not hit the nail on the head.

Expert answer

Hi Hennie,

I'd be interested to know how you found out that this is happening! Anyway, it's likely that the injector has clogged up with unburned fuel. If this is a petrol car then the best route is to simply replace the injector. A diesel injector costs a lot more though so it may be possible to go down the reconditioned route.

Hope that helps.

Expert answer

Hi Mary,

I'm afraid there is no definitiive answer to that question. Not only is every engine different, the longevity relies on other factors such as how it is driven and maintained. Honda has a great reliability record though and its engines are some of the best. Assuming it has been well maintained there's no reason it shouldn't reach 200,000 miles without an issue - and further.

Hope that helps.

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Hi Tony,

Thank you for your query. I love the Fiat Panda. It is an honest, simple car and absolutely loaded with charm - and they cost from just €7,295 under the scheme, which is really great.

The only thing I would say Tony is that time is running out for you. It is not just the issue of having a Panda in stock and getting it registered before June 30, but you also have to make sure your old car is scrapped and the paperwork is done for it before that date too! So get down to that Fiat dealership near you!

Expert answer

Hi Eamonn,

I guess a lot would depend on the price, but I didn't really rate the E-Class of that generation. It was troublesome and with that engine is pretty lifeless. My call would be the Audi everytime.

Expert answer

Hi Sean,

Out of the three cars here, by far the best value under scrappage is the Hyundai i30. You could have a petrol model for as little as €13,995. The diesel is €15,495, which is quite a bit more. If your annual mileage is small then you should perhaps save some money and buy the petrol model. I know everyone buys diesel cars these days but the petrol alternative will only cost you €52 more than the diesel each year to tax and if your mileage is low then you wouldn't see much of a saving on fuel in the diesel car anyway.

The Peugeot 308 is comfortable and good on fuel.

If you are planning on changing the new car quite soon, then the Focus will be worth the most money as a trade-in, but I think the Hyundai would be the best buy in this case for you.

I hope this helps.