Michael McAleer answers your queries
From Brian Cahill, Sligo:
I'm in the market for a new small car, something like a VW Polo, Toyota Yaris etc. I do a lot of country driving and so economy is important.
Diesels give superior economy, but these options cost about €3,000 more than petrol models - plus higher annual road tax rates.
How do these extra costs balance out over a life of seven or eight years, over 100,000 miles? Are the extra costs justified? Which is the best option in the long run?
We've dealt with this issue before, but it's worth addressing again. Initially car firms claimed the extra premium was a result of the development costs in diesel. These days it's fair to say it's merely profiteering. To be fair, some car firms now offer diesels and petrol equivalents at the same price, but at the premium level.
For the sort of car you are looking for, the petrol and diesel engines are not similar in cubic capacity.
For the Yaris, the choice may be between a 1.3-litre VVT-i five-door Luna at €15,900 or the equivalently specced 1.4-litre D-4D at €18,300. While we are always loathe to accept the official fuel figures, in this case the comparison is 48.5 mpg against 67 mpg.
Doing the maths, and given an average petrol price of 98.8 cents and diesel price of 93.5 cents per litre, over 100,000 miles the costs would be €9,248.67 for the petrol version and €6,335.56 for the diesel.
This means if you opted for diesel you would save €513. Not a sum to be sniffed at, but it depends on you matching official consumption figures over the lifespan of the car.
We've never managed it over a seven-day period, never mind over seven years. Of course, a positive point for diesel is that it usually has a longer lifespan.
But those who buy diesel models over the short term and sell them off with less than 100,000 miles on the clock, the benefits of diesel are lost on us, when the price difference is a couple of thousand euro. So, if you're going for either the Polo or the Yaris, you're probably as well off with the petrol.
From Tony Colley, Clondalkin, Dublin 22:
Is the rumour true that the two LUAS lines are of different gauges and, even if they did meet, could never carry the same trams?
This is a myth that has been running since the first track was laid. According to those in the know, both tram lines are the same gauge and trams can use either line. Tom Manning, spokesman for the Railway Procurement Agency (RPA) says: "If the two lines were connected in the morning there would be no problems at all with the trams running all the way from Sandyford to Tallaght."
From David Gordon, Dublin 22:
I agree with M McDonnell's letter (September 29th) on bus lanes. I'm convinced that 24- hour bus lanes are an easy option for the agency responsible for them and are not in anyway connected with good traffic management.
Just look at the hugely different applications throughout the city. For instance, the Stillorgan Dual Carriageway, a busy major road, has a sensible time of operation up to 7p.m., whereas the link road between the M50 and the Malahide Road junction, with one private bus operator, had a 24-hour operation up to recently.
Tailbacks caused by this ludicrous situation at weekends since its introduction some years ago were rectified only recently when the lane changed to a six- day operation. Unfortunately many of the new lanes (e.g., Con Colbert Road) are still being introduced as 24-hour.
Does nobody in authority realise that, while most of us want to and do obey traffic law, stupid and inappropriate regulations such as those on bus lane times give all traffic regulation a bad name.
Anyway, if the powers that be are so keen on 24-hour lanes, and as the times on the signs are often difficult to read, why not colour co-ordinate the times so that a 24-hour lane is on a red sign etc. Maybe that is too obvious?
• Our colleague and friend Bob Montgomery came across the dangerous signposting on the roads of north Co Dublin. He writes that motorists should "take special care if you happen to find yourself travelling the road from Garristown to Ashbourne in north Co Dublin - especially if you are doing so in poor driving conditions.
"These signs are in the middle corner of a three-corner sequence of severe bends. The first photograph shows what the approaching motorist sees at night-time. The arrows point to the right. But the second photograph reveals the true nature of the corner in daylight.
"All that was required was a little care to be taken in the sighting of the signs so that they are visible only to motorists they were intended to warn."
How many more badly sighted or inadequate signs are there throughout the country?
• Send your queries to: Motors Help Desk, The Irish Times, Fleet Street, Dublin 2 - or e-mail them to motorshelp@irish-times.ie