Freezing Fog

31 December 2006, 73,346

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I

t’s been a busy few months since the last 1451 entry and I wasn’t able to keep 1451 updated. This will be a long entry, especially after my last ten days. First off, winter didn’t arrive when I was expecting. October was very mild, where the morning temperature was typically 11°C or warmer (with one morning where it dropped to 7°C), November arrived with a frozen windscreen. The first couple of days of the month first saw me experiencing the 9-3’s auxilary coolant heater and second, having the car defrost itself.

I’ve written at length about the 9-3’s automatic air conditioning system but it wasn’t until the temperature dropped that I could experience at first hand how it behaves when the windscreen is frozen. The answer is “exactly as I’d set it up manually.” The system knows when you last ran the engine and of course the temperature of the coolant, outside ambient and inside the cabin. It sets itself up to defrost the front and rear windscreen without the driver having to touch anything. This is perhaps just how you’d expect it to behave: minimal driver input!

The other useful item of equipment that the Saab has for the winter is the auxiliary fuel heater. This is a small cylinder-shaped object under the bonnet that burns diesel for the explicit purpose of heating the engine coolant up. This aids defrosting and interior heating and it’s here because otherwise the 2·2 TiD would take a week to warm up. If you listen carefully you may hear it whining immediately after a cold engine start up but it’s very subtle. And it works... It accelerates the immediate warm up process. The unit is used if the ambient air temperature is below 5°C and the coolant temperature is below 75°C.

The penalty of the auxiliary fuel heater is that it burns fuel and this reduces the miles per gallon figures you see. It’s impossible to quantify the difference it makes because of the second factor, using winter diesel. Ordinary summer diesel freezes at -7°C whereas a winter blend of the stuff doesn’t freeze until around -29°C (at least). We’re unlikely to see it this cold in the United Kingdom (but it could be possible). However, whilst winter diesel doesn’t gel in our ordinary winter conditions it does increase fuel consumption. This is something I’ve noticed in all of my diesels but the higher the power output (and the stricter the emission control), the greater the difference. With the 9-3, so far it appears to be around ten to fifteen percent difference. Ouch.

Driving at night and with the switch to winter diesel, the Saab’s sooty trail when pressing on is all the more obvious. I’m torn between letting others suck my soot and being kind to the trees / children / ice bergs. The soot dumped into the environment is proportional to two things, one, how much power my right foot (or the cruise control system) is demanding and two, how high the engine speed is. High load and low engine speeds result in a bit of soot, low load and high engine speeds results in no soot but full power and high engine speeds results in a smokescreen! <grins>

A puncture at the end of October meant that the 9-3 needed two new front tyres. The tread depth was around 3½ mm on both sides, not worth replacing one then. The rears were also down to 4 mm and it felt tight just replacing the front tyres, putting these onto the back, only to be replacing the fronts in a few thousand miles. Thus I had all four tyres replaced.

For the replacement tyres, after careful deliberation and given my main use of the Saab (motorways) I went for Michelin Energy E3As all around. These hardwearing tyres ought to last for many thousand of miles plus they’re quiet and have a reputation for being smooth. I’ve used Michelin Energy tyres before on a company car fleet and found that fewer drivers complained about them.

We were planning to drive down to London for Christmas Day and Boxing Day, except matters changed. A close family member was admitted into hospital the week before Christmas and was in until after Christmas Day. That meant some travel between York and Boston, Lincolnshire. Each way this would ordinarily take around two and a quarter hours, depending on the weather and traffic of course. There are two main routes from York to Boston. One uses the A1, then the A17 via Sleaford, bringing you into Boston from the west. That means driving through the town to reach the hospital, which is on the east side. The alternative route is to approach from the north, crossing through Lincolnshire on the B1225. Unfortunately, the week before Christmas is not a good time to be trying to drive right through the centre of Boston... nor is driving in thick fog with the ambient air temperature at or below freezing point.

The B1225 is an entertaining road in the summer but the wrong side of “challenging” in any one of the following: ice, frost, snow, fog, mist, heavy rain. You get the picture. Thus my compromised route would be to use the A1 as much as possible, then detour via the A57 through Lincoln. Not an ideal route by any stretch but it’s possible.

Except, well the thing is I simply don’t have any exciting tales to report about the Saab during the two thousand miles other than he was remarkable for being unremarkable. Okay, one evening on the way home the Saab Information Display screen warned me that the windscreen washer fluid level was getting low. That’s it. Fifty to the gallon over the mileage (a little low I suppose for long haul trips but it was very cold), no sore back, no aches, no nothing, it simply worked and did exactly as it should.

As for running in fog with the air temperature showing -2°C, yes, the antenna ices up as do the wing mirrors, the front grill and the rear spoiler but apart from turning the radio off, these don’t bother me as I drive along.

Oh. A Happy New Year to my readers. With family in hospital, Christmas seems irrelevant and the New Year isn’t much cause for celebration, all up.