Clearing the air on winter warm-ups, Jan. 30

Last Saturday's column by Lorraine Sommerfeld on winter warm-ups was particularly well-written and environmentally significant. And the previous week's column on "zero alcohol" for all ages of drivers was socially responsible and convincingly written.

In a Wheels section dominated by male reviewers who value, above all else, aggressive styling, excessive horsepower, 0-to-100 km/h acceleration beyond belief, and top speeds well in excess of speed limits, Sommerfeld is a voice of reason and caring.

Bill Andrews, Toronto

I am a licensed mechanic, and former Drive Clean inspector and repair technician. I feel that maybe a professional take on the matter in Lorraine Sommerfeld's column is warranted.

First, I would like to comment on the "30 seconds will get the oil circulating." If engine oil does not circulate within 10 seconds, the amount of heat generated due to friction on the cam and crankshaft bearing surfaces could be catastrophic – obviously proper preventive maintenance is required.

The debate regarding moving versus idling when cold is a little more technical.

The fuel system software in virtually all fuel-injected vehicles is factory set for full rich at about minus-40 C and full lean at about room temperature. This temperature is determined by the coolant temperature sensor located in the antifreeze/coolant. The sensor is a resistor which sends a reading to the fuel computer on a graduating scale. The colder it is outside, the longer the injector pulse width (the amount of time the injector is open), which in turn richens the mixture, hence keeping the engine running.

If you add the element of load (driving the vehicle), you compound the richness of the mixture by dramatically increasing the amount of times the injector opens. Also, the catalytic convertor is virtually dead until it is brought up to proper temperature (a great way to save the environment). This is why Drive Clean tests on most cars are done on a dynamometer under load and not at idle.

A proper warm-up in the winter would entail bringing the coolant to an appropriate temperature to reduce pulse width of injector. At minus-30C, 10 to 15 minutes could potentially reduce this by 50 per cent, making the vehicle emissions lower when driving begins – not to mention giving you enough defrost heat to keep the inside of your windshield from frosting up from all that coffee Sommerfeld suggests.

Dave Murphy, Eganville, Ont.

Clarkson's Tesla review goes off the rails

Tesla: good for sex drive, Jan. 30

I usually enjoy Jeremy Clarkson's brand of candour in his car reviews, but I find it funny that his Star report on the Tesla Roadster ended up as a justification of Top Gear's deceitful review of the electric car.

I am, of course, speaking of the scene in which the car's battery "ran out of power," but didn't really. And though I do understand that the Tesla is by no means for the average buyer, it is a sign of good things to come, especially when it comes to available technology.

So while Clarkson seems to believe that hydrogen is going to be our fuel of choice at some point, it's still not really available. It's been said before and I'll say it again: hydrogen has been the fuel of the future for the past 30 years.

In the meantime, let's use available technology and improve on it.

Eli Green, Toronto

What's with the choice of ride home from Detroit?

Fuellin' around at the auto show, Jan. 23

I was surprised to see Mark Richardson's pick of the NmG to ride home from the Detroit auto show. If I were Canadian, I would be saying, "Are you kidding me?"

The NmG seems to be the invention of somebody with too much money, a "yellow sub par machine" that only does 50 km before requiring a six-hour recharge.

If that wasn't bad enough, it costs $30,000! Maybe I am completely out of step with the rest of the car-buying world here, but is anyone going to buy this thing?

Paul Oliver, Oro Station, Ont.

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