So, I'm on vacation in Dallas, and we got hit with a winter storm. As Dallas isn't regularly snowy, it lacks the removal equipment of places to the north. I played it super-safe in dealing with the driving, as I myself lack experience driving in such conditions but my FE suffered greatly, some trips clocking in under 20mpg. How do you guys deal? Any tips to keep us safer and the FE higher at the same time?
This is another reason diesels are good, low down torque so you can select higher gears and pull away without spinning the wheels, and if you get trapped, you can leave the engine running all night and it wont use much fuel! Economy will still be good.
Anyway, I dont expect you to change your car! Isnt yours an auto too? They are bad for the snow, especialy if you realise you cant slow down using brakes, I had a lucky escape a few years back, lost control on an icy steep hill, braking made the car go faster. Managed to slow it using 2nd, then 1st gear and came to a gentle crawl. My neighbour the following day, in her auto, wrote her car off on the same hill the following day.
Some decent tyres might help with traction issues, only worth the expense if the shows going to be around for a while though. Otherwise, drive extremly slow and leave huge gaps between you and the car in front, at least ten times greater than regular driving. Try not to brake at all, let the car slow itself down etc.
I was taught to drive in snow by my grandmother, who lived in Connecticut - in a RWD Buick. I'm very good at it, but my recommendation is if they don't treat or clear the roads, and you don't know how to drive in it, stay home. As far as the fuel economy goes, mileage always tanks in the winter, snow and ice just makes it worse. No way around that.
Alright. So, basically, just stay safe and don't worry about your economy, because there's nothing which will help that anyway. Sounds good to me!
We usually get one good dump per year. I had generally been able to avoid going anywhere on those days, but the last couple of years I haven't been so lucky. I use common sense...no sudden inputs, etc. and I really have never broken traction to speak of.
The extended warm up period is what kills you. Low tire pressure hurts too, and driving on unplowed roads is also bad for mileage.
My own experiences with MPG and snow, I've done a few highway trips in the mountains and near my house in heavy snow conditions, in my FWD Scion shod with studless snow tires. Driving on plowed roads with the proper tires allows me to drive at normal highway speeds (about 60 mph here) and I've been able to get my normal highway MPG in those conditions. I haven't seen much dropoff unless driving on unplowed roads, or if I don't check tire pressure first (you always need more air after a snow).
Regarding engine braking/coasting in gear to maintain speed down hills, it's a bad idea in the snow. It's much easier to modulate braking force with the brake pedal... turns out that's what it was made for! The brakes stop the car using four wheels whereas engine braking only brakes the driven wheels. When coasting downhill in the snow, for example, if you are traction limited, adding the braking force from engine braking to the front wheels will usually cause them to lock up easily when you apply the brakes, before the rear wheels do any braking work.
If you can't use the brakes to stop the car, and if you don't have ABS to do it for you (or if there's not enough traction for ABS to help), then you shouldn't be driving. That's just common sense -- if you can't keep from locking up the wheels when you want to stop the car, you're endangering yourself and others by getting behind the wheel.
Engine braking in very cold conditions for long periods (i.e. down long hills) should also be avoided for longevity reasons. It cools the motor and oil off very quickly, by pumping cold air through it without burning any fuel. Not only is this bad for the motor (in the same line that cold starts are bad for wear) but it's also bad for fuel economy, because the motor runs rich, as if it's just been cold started.
I'll add a counterpoint/addendum to Jay's post. While experience driving in snow is really important, it still doesn't make it safe to drive if you don't have the right tires. If you HAVE to drive in the snow, EVER (i.e. if you can't call in to work because of snow) then you need to have the proper tires. Getting a second set of wheels with some studless snows is cheap for most cars, and a front-drive car with the right tires is far, far safer and more capable than a 4WD car with all-seasons. Again, driving a car in snow or ice without the right tires is just turning it into a 2-ton projectile and you're endangering yourself and everyone else on the road by doing it.
I think I'm ok on the safety part - just didn't know if it could be combined with extra MPG. I don't see any way to gain mpg without severely sacrificing the safety part, so I'd consider the issue closed. Thanks for the input!
Yeah, extended warm up time sucks. Regardless of whether snow on the ground or not. A grill block will help along with improving aero some. There are other measures, but they are likely not worth the effort if near freezing or lower temps aren't the norm.
Should have been clearer. I use the 'lower' gears to prevent the car from speeding up too much on a decline. Specially with traffic. Sometimes a light tap to the brakes can cause lock up. Better not to have sped up in the first place. Good point on it cooling off the engine though.
Snow tires are worth the investment if you regularly drive in snow. In the North East US, they do a good job of clearing them. So snow tires will be hurting fuel economy most of the time. All the time if you have a job that lets you avoid driving in the white stuff. The only time I was driving in it this year, was twice and by choice. So was the sliding I did.
I should check my tire pressure, but it is just too cold. I've overshot my target psi when it wasn't freezing by 1psi for every 10F drop I expected, though.
This can lead to a debate, but I also figure the lower pressure means better traction, but I also regularly run over the car's rating.
Personally, I haven't been able to notice a difference in mileage between my Toyo snow tires and any of the other tires I've ran on the car* (both all-season and summer). Long as I keep them aired up they all seem to deliver about the same mileage. I don't see why they would either, as they are a very hard compound.
But, I have never used low rolling resistance tires either... but even then, there are many LRR choices in studless winter tires.
*Caveat is the DOT-legal racing tires on my MR2, which definitely cost a couple of MPG, but I've never used these on my Scion.