Hello all,

I still have about 25,000 miles of data to enter for my non hybrid Scion XB 5 spd. My recent averages have been running ~40 mpg but I'm starting to take a hit with the cold temps. I'm hoping some of you experts can give me some tips. Thanks for your help in advance.

Only tip that universally works is often not palatable: slow down. Other than that 'biggy,' you can tweak tires pressure and opt for less rolling resistance, lighten your car and of course feather touch the accelerator while anticipating stop signs and traffic signals. Since you drive a 'low powered' car, reducing the AC and keeping windows up will probably help in the moderate temps?

I'm not sure additives are much of an answer, as I remain skeptical, but some have suggested that there are some 'snake oils' out there that might offer a fractional increase in mileage particularly with winter fuels.

I'm probably one of the few left still doing this, but I add a piece of cardboard to my radiator in the winter to assist in keeping the engine bay warmer ... but then I drive a small diesel with insulation on top and underneath and they are a pain to keep warm while idling in cold weather anyway. Good luck and welcome as one of a handful of non-hybrid drivers here. (I'll own one as soon as they bring me a diesel! )

--RichC --- "My Desultory Blog" & CinciTDI Club

Hi MOXB,
Welcome to the forum. As RichC suggested tires are one of the best ways to make a noticable increase fuel economy besides changing your driving habbits. A lower viscosity oil will make a substantial difference too. 0W-30 fully synthetic is a safe bet or even 0W-20 if you can get clarification that it's okay to use in your engine.

I am currently running my tires at 40 psig, am good at timing lights/coasting to stop signs, and generally drive as conservatively as traffic permits.

I understand higher effeciency is obtained at higher engine/ air intake temperature but could use some instruction. My water temp. is usually up to 180-184F within a few minutes (I use a scan gauge to monitor the engine), which is as high as it ever runs. If I block a portion of the radiator then it should reach operating temp. slightly faster but is there any advantage after that? Won't the thermostat open and fan come on to maintain the temp at 184F?

I'm interested in a warm air intake mod. but have verry little room in the engine bay. I'm wondering though, since the intake is on the left side of the engine bay can I block the grill on the left side to increase the intake air temp?

Thanks for you suggestions,

Mitch

The radiator thing is something a bit more specific to small diesels in cold climate. These little beasts are so highly efficient nowadays that keeping them warm when at low RPM is a problem. Most gas engines do not struggle in that regard quite as much ... and unless your vehicle is a hybrid or doesn't waste all that much heat in keeping things going it will probably not make too much of a difference. (not even sure it does for me.)

On the physics side of things ... less wasted heat that is not used for mechanical momentum ... the more efficient the potential. This is sort of why a few of us favor using a small 'biodiesel' powered hybrid vehicle as a realistic option to gas hybrids. Both improve on how efficiently we use the fuels we burn BUT with the added longevity of a diesel, the efficiency of the fuel, the option of a 'variety' of bio based fuels including algae ... IMHO a diesel coupled to the hybrid concept would be another excellent option.

--RichC --- "My Desultory Blog" & CinciTDI Club