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Old 02-12-2014, 03:25 PM   #11
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Looking at your charts, see a small drop for Dec. & Jan. & a larger at the Feb. bar. Looking down to the next chart, there were three fillups with low mileage (relatively) and the MPG is jumping around a bit.

IMHO you've got nothing to worry about yet, unless the trend continues in warmer weather once Summer tires & wheels are installed.

When I went from 15's to 17's for Summer tires myself, there wasn't a noticeable mileage penalty - but it was HARD to drive even 1 tank ALL in economy mode - too much temptation to have a LITTLE fun here & there. Long trips on the 17's gave the best mileage - optimum when I could stick to 67 cruise.

Another 4 cyl. vehicle I've run for years, with economy summer tires & separate winter wheels & snow tires was consistent at 30 mpg summer, 25 mpg winter. Last three years it hasn't been used as much, run on 1 set of snows all year getting 25 mpg.. I mention this one because of 18 yrs. experience with the one vehicle.

So - individual tire differences aside, Snows are noticeably worse for MPG than summer tires.

Now for cold weather, even once you set aside more fuel for warm up/spinning tires/winter fuel questions/air resistance/etc., you still use more fuel just because of the cold air. A number of factors affect this, from denser air to poor fuel vaporization, all requiring a bit more fuel for the right mixture to burn in the engine.
For an extreme example, ask a snowmobile owner about jetting for 0-35 degrees vs. -30 to 0 degrees. A sled jetted for temps. above zero will often run great in below zero weather, until a piston melts from the high temperatures of running such a lean mixture. Many (most?) have gone to fuel injection which compensates automatically for temperature changes, just like our cars.

So, more fuel used in the cold - even leaving aside all the causes that lead to debate over their magnitude in individual circumstances.

Snow Tires + Cold Weather = Poor MPG.

With all the variables in the Winter, only a large change in mpg. during the Winter is worth investigating as a sign of problems with the car (like 25 to 15 in similar conditions). Better to wait for Summer to "tweak" the car for the best mpg..

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Old 02-12-2014, 03:31 PM   #12
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Quote:
Originally Posted by crice8 View Post
An intake will increase your mpg if you maintain the same driving habits as before. increased efficiency = more mpgs
Increase efficiency, ha so debatable. It would be hard to prove, but I HIGHLY doubt a intake will be more efficient at all times, or even at a time. Suck air through a toilet paper roll, then suck air through a paper towel roll, you tell me if you notice a difference. Compression pulls the air in, it does not suck it in so to speak nor does it flow in.
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Old 02-13-2014, 02:20 AM   #13
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Originally Posted by SlickWilly View Post
Increase efficiency, ha so debatable. It would be hard to prove, but I HIGHLY doubt a intake will be more efficient at all times, or even at a time. Suck air through a toilet paper roll, then suck air through a paper towel roll, you tell me if you notice a difference. Compression pulls the air in, it does not suck it in so to speak nor does it flow in.
Your argument is invalid. Engines are air pumps. Anything that makes it easier to breathe makes it more efficient. More HP, more mpg, ect. It's like trying to suck air through a squiggly straw, and then say it has as easy as a straight straw.
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Old 02-13-2014, 05:43 AM   #14
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Quote:
Originally Posted by sailor View Post
Looking at your charts, see a small drop for Dec. & Jan. & a larger at the Feb. bar. Looking down to the next chart, there were three fillups with low mileage (relatively) and the MPG is jumping around a bit.

IMHO you've got nothing to worry about yet, unless the trend continues in warmer weather once Summer tires & wheels are installed.

When I went from 15's to 17's for Summer tires myself, there wasn't a noticeable mileage penalty - but it was HARD to drive even 1 tank ALL in economy mode - too much temptation to have a LITTLE fun here & there. Long trips on the 17's gave the best mileage - optimum when I could stick to 67 cruise.

Another 4 cyl. vehicle I've run for years, with economy summer tires & separate winter wheels & snow tires was consistent at 30 mpg summer, 25 mpg winter. Last three years it hasn't been used as much, run on 1 set of snows all year getting 25 mpg.. I mention this one because of 18 yrs. experience with the one vehicle.

So - individual tire differences aside, Snows are noticeably worse for MPG than summer tires.

Now for cold weather, even once you set aside more fuel for warm up/spinning tires/winter fuel questions/air resistance/etc., you still use more fuel just because of the cold air. A number of factors affect this, from denser air to poor fuel vaporization, all requiring a bit more fuel for the right mixture to burn in the engine.
For an extreme example, ask a snowmobile owner about jetting for 0-35 degrees vs. -30 to 0 degrees. A sled jetted for temps. above zero will often run great in below zero weather, until a piston melts from the high temperatures of running such a lean mixture. Many (most?) have gone to fuel injection which compensates automatically for temperature changes, just like our cars.

So, more fuel used in the cold - even leaving aside all the causes that lead to debate over their magnitude in individual circumstances.

Snow Tires + Cold Weather = Poor MPG.

With all the variables in the Winter, only a large change in mpg. during the Winter is worth investigating as a sign of problems with the car (like 25 to 15 in similar conditions). Better to wait for Summer to "tweak" the car for the best mpg..

Cheers!
Great writeup. The weather makes a lot of sense. The biggest change I saw was when I put the wheels/snow tires on. So combine the most likely heavier tire, with more wheels spin, and the sub zero temps weve been having here, now I can see why it would go down.

But is there anything I can do as of right now to pick it back up?

I heard about a free mod with your throttle body. What does that do? Ive also heard something about the baffles (flaps?? maybe) in the intake manfiold itself. Will this help my mpg?

Ive been trying to do more coasting than normal, and shorter shifting than normal to see if that helps.
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Old 02-13-2014, 11:37 AM   #15
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Quote:
Originally Posted by jwindbigler View Post
Your argument is invalid. Engines are air pumps. Anything that makes it easier to breathe makes it more efficient. More HP, more mpg, ect. It's like trying to suck air through a squiggly straw, and then say it has as easy as a straight straw.
The argument actually is entirely valid. Additionally, anything that improves maximum airflow capacity does not necessarily improve fuel economy either.

Specifically in regards to this conversation, at low throttle inputs the engine does not require large quantities of air to flow through the throttle body, or consequently the intake system. Breath in deeply and quickly through your nose, and notice how much more difficult and restrictive it becomes than when breathing through your nose regularly. Even though larger nostrils might improve your ability to breath through your nose while working out, would larger nostrils noticeably affect your ability to breath regularly while sitting at a desk?

The effect of going from a 2" minimum ID (3.14 in^2 minimum flow area) ribbed inlet pipe to a smooth 3" ID (7.07 in^2 flow area) inlet pipe leading up to the throttle body is going to be greatly reduced if the throttle only has 0.5 in^2 of open flow area. In theory there should still be *some* benefit due to the reduced turbulence and pressure drop through the intake system, but at low flow rates the realistically detectable difference is certainly debatable.
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Old 02-13-2014, 12:11 PM   #16
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Quote:
Originally Posted by Driven5 View Post
The argument actually is entirely valid. Additionally, anything that improves maximum airflow capacity does not necessarily improve fuel economy either.

Specifically in regards to this conversation, at low throttle inputs the engine does not require large quantities of air to flow through the throttle body, or consequently the intake system. Breath in deeply and quickly through your nose, and notice how much more difficult and restrictive it becomes than when breathing through your nose regularly. Even though larger nostrils might improve your ability to breath through your nose while working out, would larger nostrils noticeably affect your ability to breath regularly while sitting at a desk?

The effect of going from a 2" minimum ID (3.14 in^2 minimum flow area) ribbed inlet pipe to a smooth 3" ID (7.07 in^2 flow area) inlet pipe leading up to the throttle body is going to be greatly reduced if the throttle only has 0.5 in^2 of open flow area. In theory there should still be *some* benefit due to the reduced turbulence and pressure drop through the intake system, but at low flow rates the realistically detectable difference is certainly debatable.
I guess thats what was saying. It does have an effect. Most likely not a significant one, but its still a slight increase.
In regards to the invalid argument, I was talking about the part where hes talking about a toilet paper roll compared to a paper towel roll and breathing through it.
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Old 02-13-2014, 02:12 PM   #17
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Quote:
Originally Posted by SlickWilly View Post
Increase efficiency, ha so debatable. It would be hard to prove, but I HIGHLY doubt a intake will be more efficient at all times, or even at a time. Suck air through a toilet paper roll, then suck air through a paper towel roll, you tell me if you notice a difference. Compression pulls the air in, it does not suck it in so to speak nor does it flow in.
Hmmm. I don't tend to suck on things... I will leave you to do what you please...
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Old 02-13-2014, 02:25 PM   #18
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"What is the Increase in Fuel Consumption When Using A Cold Air Intake
Ideally, cold air intakes should reduce and not increase fuel consumption, as they introduce a higher amount of oxygen into the engine, thus aiding in more efficient burning of fuel. However, it will usually turn out to be the opposite because installing one will normally change your driving habits. A cold air intake will cause your car to roar and this new sound causes most people to push the gas to the floor as they enjoy listening to the powerful sound from their vehicles. Flooring your gas pedal means you will be consuming more fuel. So to keep your fuel consumption down, you should work at resisting the temptation to push your gas pedal to the floor."

Source:
http://www.carsdirect.com/car-mainte...ne-performance

And for a scientific explanation with actual evidence rather than just a "debate."
OP this also contains very useful information on how to increase your mpgs in the mean time.
http://www.science20.com/simple_solu...ve_our_economy
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Old 02-13-2014, 02:33 PM   #19
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And to those who claim against you probably fall into the later half of this statement.

"Does Air Intake affect Gas Mileage?

Studies have shown that cold air intake gas mileage amounts are about 5 percent better than if you don't use one on your car. The cooler air is denser and usually gives the vehicle additional oxygen for your engine to burn. In turn, this can increase the horsepower and give you more fuel mileage for your money. Sometimes though, this 5 percent or so increase is not seen by the driver, because if you drive too fast or otherwise don't take care of your car, you won't benefit from it since it is a somewhat small amount. So, it's your choice whether or not to use one on your car or truck."

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http://www.carsdirect.com/car-mainte...ve-gas-mileage
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Old 02-13-2014, 02:34 PM   #20
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Here is our cars (Crice8 Video) with a header, exhaust, intake, tune and lightweight wheels.
http://s1217.photobucket.com/user/et...O0014.mp4.html

Here is our car's bone stock SES on SES wheels with leather interior and everything, stock down to the filter
http://www.youtube.com/watch?v=uVZNC1MSg9E

Y'all let me know how efficient all those mods are. I believe Crice and I even get very similar gas mileage. The best way is to keep keeping track of it and try to drive a little more grandma like.
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