Given our local temperatures, it is probably very safe to start the engine and just drive off at a relaxed pace. It will probably take longer to warm up the transmission fluid if you're not moving the car.
My understanding of spark plugs is that:
- cold plugs are thermally more conductive than hot plugs. They are meant for aggressive driving styles as it takes a higher engine load to keep them at optimal temperatures. Low plug temperatures will accumulate carbon deposits because there is insufficient temperature to burn it off. Excessively high temperatures will damage the electrodes.
- hot plugs are less thermally conductive and these are specified for our cars as engine loads tend to be lower and the plugs need to maintain an optimal temperature to prevent fouling.
But as always, I could be wrong.
When shifting to N, the forward drive clutch disengages. This is NOT the torque converter. It is debatable whether shifting to N while at speed will damage the transmission. In any case, I shift to N at red lights. It reduces my engine load and fuel consumption while avoiding vibration. Having the engine turning the torque converter while the output shaft is held stationary will only heat up the transmission fluid... I have connected ScanGauge to a Jazz CVT before and found that shifting to N while stationary will reduce fuel consumption.
For the Latio CVT, torque converter lock-up occurs at speeds above 18km/h. If you release the accelerator above that speed and keep the shifter in D, the ECU will cut-off the fuel. Because the HR15DE does not have valve shut-off (like the Civic Hybrid), the engine will act like an air pump and you will feel the car decelerating at a higher rate than if you shift to N. I am guessing that fuel cut-off is cancelled when engine speed falls to about 1100rpm or when the toque converter is unlocked. When the Latio TCM (transmission control module) detects a downslope, it will drop the CVT gear ratio to increase engine brake force. This will slow the car even more. This is less obvious/ negligible if you enter the decline at speeds above 70km/h.
You can sometimes cancel the torque converter lock-up by releasing the accelerator and then gently tapping it again and letting go. This only works at speeds below 60km/h. This is useful when coasting downhill around bends--you don't want to slow down, but you don't want to have the car in N either (for safety's sake).
My personal style is to take my foot off the accelerator when I anticipate the lights wrongly or if they are unpredictable and I need to stop fairly quickly. If I see a red light far ahead, I will shift to N and allow the car to coast to a stop.
I think the HR15DE + CVT is a fairly good set up for hypermiling. I imagine that holding a steady 75km/h on highways without air-conditioning will return close to 24km/L. Personally, I have not achieved this before. However, it is possible to get an average of 21km/L over a tank of petrol if you have the right route and driving style.
