Stuff you can do to improve your winter mileage

Thanks for the tips!

 

In one thread it was briefly mentioned that leafs in certain intakes could be reducing efficiency. Anyone able to provide a listing of places to be checked, maybe with some photos as well?

My current tank has been significantly lower MPG and also I think strange/different noises from under the hood than I used to have.

 

Hi Qui...,

The main place where a leaf can reduce mileage is in the intake plumbing. Usually the leaf will get pulled into the air cleaner housing, and be blocked from going further by the air cleaner. So, just pull open the air cleaner and look for any debri. You could run a coat hanger bent straight down the intake tube (NOT towards the engine) to be sure it has nothing in it that did not get pulled into the air cleaner housing.

Check the air cleaner too. Hold it up to the sun and you should be able to see the glow through the filter cloth. If not, replace it. Its supprising how quickly the filter will become solidly blocked like that. Mine went from acceptable to opaque in about 6 months between 18 and 24 K miles, even after I had reverse vacuumed it at 18 K miles.

 

I found in winter with full grill block the engine coolant T is also about 10F higher than before the grill block. So the same effect is achieved with grill block as with the thermostat change. Of course the amount of blocking needs adjustment according to outside T. So it is not as easily controlled as the thermostat method.

 

Latitude and Geography Matter: Given that it is winter in the Northern Hemisphere, it stands to reason that your fuel-saving examples are mostly oriented to methods that enhance mileage in cold weather. I live in Southern California, where it will approach the low 80 degrees F today, making some of these tips barely relevant. During much of the summer, not running the A/C is this climate might qualify as a form of suicide and, depending on the passengers, could also be counted as child abuse. Today, it might be a challenge for someone in many northern latitudes of the US to identify with what it is like to drive three kids around Palm Springs on a July day in a Prius with A/C turned off. Obviously the coat, gloves, heater block, and lowest blower setting will be no starters in this scenario. Anyone who drives a dark colored car will quickly discover that no A/C during California summer conditions makes as much sense as taking a cold shower and then plowing around Buffalo today with the heater off, buck naked, and windows down in your shiny new Prius. I suppose that, in addition to normal fuel economy steps that apply to California driving, I can run the A/C as minimally as possible during the summmer; switching it off during uphill stretches and to a slightly colder setting for those inviting down hill glides.

 

efusco recommends that tire pressure should be at 44 and 42 pounds for best mileage. The Toyota dealer when changing my oil yesterday commented that my pressure was way too high and will eat up the middle of the tire and is also unsafe in winter when you want the most tread touching the pavement/snow/ice/snow.
I purchased Nokian wrg2s today and want to feel safe more than saving a few dollars. Is there a middle ground, and does anyone have a sound reason that 44 and 42 are safe?
sincerely

 

Since the '08 genll doesn't have a heat guage, how do you know when it's OK(for vehicle wear and tear) to put it in "D" and go?
Resident of NW Michigan
thanks again

 

Not knowing what type oil was put into your car, I will say that many GEN II drivers on this forum are using 5W-20 or even 0W-20 synthetic oil. With that viscosity, it is safe to put it in "D" and go immediately. If possible, try not to exceed 35mph for the first five minutes or so. Even the Toyota recommended Dino Oil is safe to run immediately if you start out slow and temps are >0F.

Attempting to "warm up" the car while sitting idle in the garage (or wherever) for X amount of time is a waste of fuel and not particularly productive. The reason being is that the only thing heated is the engine and catalytic converter. You're still starting out with cold wheels, bearings, and joints that should be warmed up in conjunction with the ICE if run right from the start.

Tire pressure at or near the tire max-rated pressure is perfectly safe. As far as high pressures causing the center of the tire to wear out before the edges, that may have been true back in the 'olden days' when most tires were bias-ply instead of radials, but with today's tires, the car manufacturer recommended pressure is more likely to result in excess outer tread wear than in even tread wear. It also results in LESS tread contact with the road than a higher pressure. I live in SE Mi, and I run my tires at 51F/49R. I'm not going to advise you to exceed the max tire pressure, but use your own judgement on what pressure to use.

 

There is are age old debates about whether to use mfg suggested tire pressures or choose your own based on experience. With some cars, I measure tread wear and make adjustments if necessary. With my Prius, I go for highest pressure to make the tires roll easy until the ride is too rough to accept. That means for me I keep the pressures up at 44 or so all year round. I just rotated my fronts to the rear after about 50K miles and the treadwear was perfectly uniform. As long as the tires themselves are rated for the higher pressure, you should be fine.

Good luck!

 

Outdated info or not, center tread wear is the least of your worries if running with your tires inflated to near, at, or beyond the Max. Press. printed on the sidewall. The more serious concerns are (in no particular order):

- Blowouts (a.k.a. catastrophic failure of the sidewall). If the tires are at maximum pressure when cold, when the tire heats up as the car is driven, the pressure inside increases beyond the maximum. The higher the pressure, the lower the amount of sudden external force that's required to cause a blowout or tread separation. Think of two balloons, one inflated to full size, one inflated a bit further so the rubber is very tight. Which one will fail first if sat on? (Hint: it's the overinflated one.) So that pothole you didn't see in time to avoid can either shake you up or break you up. Ever been in a car when it suffered a blowout at highway speeds? I haven't myself, but everyone I know that has says it's a frightening experience to say the least. Speaking of which...

- Loss of control in an emergency. Let's not forget that the tires are the only part of the car in contact with the road. The tires' primary job is to make sure that the 3,500lbs the average car weighs goes where you want it to. All 3,500lbs of car is supported by an area totaling (from all four tires together) roughly the size of a an 8.5x11" sheet of paper when the car is stationary. This contact patch gets even smaller when the car is in motion due to the centripetal force applied to the tread as it rotates and the increased pressure caused by the heating of the tire as it flexes during use. Also, the size of the patch varies inversely with vehicle speed, so the faster you go, the smaller the patch gets. Raise the pressure in your tires to maximum and the contact patch shrinks even further, making the tires' job that much more difficult. DEER!!!

Either of these conditions can result in serious damage to your vehicle and/or private/public property, as well as injury or death to yourself and/or others. Will inflating your tires to maximum save you money on gas? Yes. But not much, especially in contrast to how much it could cost you to replace a damaged tire and/or wheel and/or frame and/or leg and/or etc. 15,000 miles / 45 mpg x $2.75/gallon = $916.17/year in gas. Inflating your tires to maximum will only net you 2-3MPG at most. So, at 47 or 48MPG, that's only a savings of ~$40-$60 for the whole year. I'll wager that your insurance deductible is higher than that, probably by an order of magnitude. Whereas the potential costs of highly over-inflating your tires are much larger still.

That all being said, it should be relatively safe to over-inflate to 10% above the car manufacturer's recommended pressure for fuel economy purposes. Doing so will still get you 1-2MPG without drastically compromising safety, handling, or ride quality. However, inflate higher than that and you rapidly encounter the law of diminishing returns where you get less gain in MPG for each PSI increased.

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