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Old 09-20-2013, 08:56 AM   #40 (permalink)
paulgato
EcoModding Apprentice
 
Join Date: Sep 2013
Location: Oxford, UK
Posts: 126

Black Beast - '02 VW Goff Estate S
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Quote:
Lower (cold) weight oil definitely helps in the first miles.
Engine uses notably less fuel and is less noisy.

Once warm, the effects are small though, so the effect on your overall FC depends on the length of the average drive.
Thanks Euromodder. In winter most of my journies are short, local, work-related ones.

Using cheap mains electricty to warm the engine up rather than using expensive diesel to do that job makes sense to me. I also notice that on a long journey, the mpg goes up and is at its maximum after about two hours' cruising. I'm guessing this is not engine-related (the engine should be pretty-much heat-soaked after half an hour?) but related to other parts of the drivechain warming up, e.g. the gearbox, axles, CV joints, wheel bearings, tyres, etc. Hence wanting a heater on the gearbox as well.

Ultimately it would be very cool to use solar-charged auxilliary battery power to run the heaters. They could be on a timer to come on a couple of hours before drive-time.

Ultimately, ultimately, it would be super-cool to use that auxilliary battery (charged either by solar or by mains) to also replace or supplement the alternator. I.e. to use the aux battery to run a voltage-regulated 'charger' for the main battery so that the alternator 'sees' a high voltage most of the time and doesn't bother generating amps. For daily short journies, or for longer trips with lots of rest time, the solar regeneration might be enough, and when it isn't, the car can be plugged into the mains to top up the aux battery. And with that kind of arrangement, even if the solar isn't enough, or the mains charge doesn't completely negate the need for alternator charging on longer journies, any solar/mains power you can put in WILL save you a corresponding amount of fuel. Mild hybridisation.

That all would need a bit of electrical/electronic design/calculation, plus some investment of course. I think it should be feasible but first I'll try with a couple of pad heaters. (Maybe 12 volt ones so they can be used in any future solar/aux battery arrangement.)

Sorry - thinking aloud, ...kind of. I've been thinking about this over the last couple of days. My feeling is it would work. Probably cost-neutral at best, but you get the added benefit of quicker, more comfortable winter morning starts where the cabin heater kicks in much sooner.

Last edited by paulgato; 09-29-2013 at 07:46 AM..
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