Poor Fuel mileage in cold weather

[Joe D 2]

I have an 03 Sport Trac 4x4. When i got the truck late 07 I was getting about 16 mpg with then it got colder in Wisconsin and it went down to around 14 -14.5. Last January I installed a Volant cold air intake. No noticable changes to mileage. In spring I put a scan gauge in the truck. Over the summer days when outside temps were upper 80s my trip mileages were getting up to 18.8 mpg. Tank fuel mileages with both the scan gauge and the odometer were upper 17's most of the summer. As it got colder out coming into winter I noticed that the instant economy readings while cruising were lower than my trip mpg in the summer. I started experimenting with getting warm air into the air box with some increases in mileage. Last week I put a heater core in front of the opening in the box for my cold air intake. Most of my driving since it has been between -5 and 15 degrees outside temps. The scan gauge has been showing around 60 degrees incoming air temp and my trip mpgs have been about 17 when they were 14.5 or so before the heater core. I'll have to wait a while to know for sure how consistent this is going to be. I haven't yet run a full tank of fuel with this setup and I think tomorrow is supposed to be the start of a big warm up heading to 40's so that will change up my experimenting for a little while.



Any body else ever try anything with a warm air intake before? It seems crazy I know, but my 1988 Ranger 4x4 with the 2.9L I had before this truck got 19 to 20 mpg year round whether it -10 or 90 outside so I just couldn't understand why the Sport Trac falls so bad cause it gets a little cold. But now I'm thinking its just the computer program. I have also noticed the exhaust temp runs about 200 degrees higher while driving on the freeway when it gets cold out as compared to when its warm out, so I guess the extra fuel is just heating the exhaust.

I'll try to post some more later when I get some more miles on. I opened up my coolant valve some more tonight to bring the incoming air temp up a little more, but like I said with warmer temps coming for a week supposedly I'm probably gonna have to close it some to keep the temps from getting to high.

 

[Jim parnell]

your mpg's sound about average for the different seasons, mpg will really be bad @ cold start up at the temps you mentioned, suggest installing a block heater or oil heater to shorten warm up timefrom cold start. Do you park the ST inside at night or outside? Could try a partial radiator block/cover to aid in engine warm up as well. The increase in mpg after installing the add'l heater core is a good start, but you're not gonna get great mpg in an ST 4x4, just not gonna happen. 17 in the winter time temps like that are good imo.

 

[Todd Z]

Cold air is more dense...... usually more fuel is needed since there is more air....



Thats the basic theory of it..



Todd Z

 

[Tom Schindler]

Cold air is more dense...... usually more fuel is needed since there is more air....



Thats the basic theory of it..

Just to add to Todd's comment, lets not forget that you engine wants to run warm. It does not like to be cold. When it is cold outside, more fuel is used to help warm the engine up. Since the weather is cold, it takes longer to warm the engine up.



Add the fuel blends are different in the winter, that has an impact.





Tom

 

[Mark K 2]

Most Wisconsin gas stations sell E10 as regular gasoline in the winter. The only way to tell if you're getting E10 is to look for the small sticker on the pump that says "contains 10% ethanol." And they sell it at the same price as 100% gasoline.



I get about two MPG less using E10. That's why I buy from BP stations in Wisconsin in the winter. They don't add ethanol.

 

[EddieS'04]

In texas we have E10 year round. Mpg suffers year round. Winter is worse.

 

[Chris Taylor]

Be careful of the BP winter blend too. For years, they had what they called "Ice Guard" in their gas, which was 5-10% METHANOL. I don't think there is a law that says they have to tell you that, because methanol is a different alchohol from ethanol. Does the same thing, but costs a little less than ethanol(at least it did before all the ethanol plants sprung up...).

 

[Bill V]

Mark K, I thought I had heard that both MN and WI (and perhaps others) had changed a few years ago, to using E10 year-round, instead of making it only a "winter blend". Also, I thought that it was (both back when it was a winter-only thing, and now with it being year-round) a legal requirement for all stations, not something which varied from station to station. Do you know for sure what the situation is? (In either state?)

 

[Todd Z]

I Forgot to mention,



A little FYI.



That your PCV and your Throttlebody are HEATED in the winter time when you have your heat on inside the truck...



This also warms the air going into the engine, making things even worse...



I bypassed mine....



Todd Z

 

[Joe D 2]

Todd Z, I noticed the coolant lines running to the PCV and throttle body. You say that heating the air going into the engine makes things worse? How so? What results have you had by bypassing that stuff. I'm heating all the air that goes into the air filter now and so far I have seen an increase of 2.5 mpg. The engine seems to like the warmer air. Have you seen any improvements by not heating the throttle body and PCV?



jimp, As for the cold starts I used to think that was where my mileage went in the winter, but watching the scan gauge instant economy read only 16 mpg while cruising at a steady speed on flat area of road 5 or 10 miles after the motor reaches operating temp suggests its impossible to get a decent average economy while the motor inhales cold air. So I guess I'll try to get rid of the cold air at least once the motor does get warm.



Its a little dissapointing that twenty years ago, 4x4s where built this wonderful thing that I think only the Ford Superduties have anymore. You just turned the lockout to "free" and you pretty much had the same rolling resistance 2wd. Why would such a great concept fade away with time? I would guess cause people have gotten too lazy to get out and lock in the hubs, but really those people could have just left them locked in and had the same wasteful situation we are all stuck with now, a front axle which always turns whether its needed or not.

 

[Johnny O]

1. People are too lazy to get out to lock and unlock hubs.

2. More sales to the soccer mom demographic, who are mostly not mechanically inclined. I once rescued a babe in an S-10 Blazer who was stuck in the snow by saying "Put it in four wheel drive" and she said "How do you do THAT?" :wacko: Afterward she thought that 4wd was pretty cool.

3. At least here in the frozen north, road salt would corrode the good steel hubs and you'd need to keep Vise-Grips in your glovebox to turn them. Ford's solution was hubs with plastic innards, which break easily.

4. Ford's own testing revealed that if you use synthetic axle lube, the mpg loss with live hubs was 0.3 mpg.

 

[jamie frenzel]

I live in wisconsin too. I am also wondering about the bp gas? I use shell and it contains 10% ethanol. My mpg are 18-20. 2 wheel drive though.

 

[Jim parnell]

Filled up here in E TN @ BP, pump said 10% ethanol in all grades.



FadetoMud: You can try removing the CAI and go back to stock for wintertime but the mpg you're getting is about average for an ST, and mpg goes down in wintertime for various reasons, no way around it. You can checkout CleanMPG.com or Ecomodder for hypermiling techinques and suggestions/info which may help you in your quest for better mpg. I have a SGII in my 07 V6 2WD, and my dfe is 21 except in really crappy weather, its been cold here in E TN but not like your weather by any means, have noticed that it takes about 5 miles for my tranny fluid to warm up sufficently for the TC to lock up and reduce my rpm's at 50 mph or more, which affects my dfe by .5 or more on my 07.