AFE stage 2 intake

[JP7]

I'm no rocket surgeon, but I have a feeling it has to do with the quantity of moisture in oxygen being reduced in colder temperatures.
The computer compensates as best as possible to change the fuel/air composition, but a tune improves that.

I stand open to be corrected on this, I'm just speculating based on my building science experience with energy management.

 

[Squatting Dog]

That is why I am concerned about the weld on the inside of the tube. Ideally, you would want it as smooth as possible to keep airstream flowing smooth as possible. With sloppy welding could cause disturbance in airflow (eddies and turbulent vortices) and slowing it down. Allowing some heat gain because of heat transfer from tube and molecular friction caused by turbulent flow.



-Greg

 

[Deinonychus]

Winter blend gas usually is the cause for poorer gas mileage in this time of the year.
I had done a statistical test over a two year period with a V6 2000 Oldsmobile that showed a statistical difference between the gas mileage in the summer and winter. The winter blend gas has more volatile additions and thus less BTU's than the summer gas (is my guess). It accounted for about a one (1) mpg difference.

 

[f16YODA]

Hey fellas, the main reason is air density. Much like when you add forced induction, you need more fuel to compensate for the higher density air charge. Colder air = denser air, so the computer adds more fuel. That's also why a jet aircraft performs significantly better in cold weather. Denser air through the engine.

Though, I wouldn't be surprised if some of the additives make a little bit of difference, also.

Here's something else to consider...how often do you let your truck idle in the winter to warm up? My mileage plummets here in the winter since I have to run my truck for 10-15 minutes to warm up. Especially when its 40 below! Just another thought.

Have at you!
- YODA

 

[whtrapta]

I know that about the warm up. My truck doesn't really average 11 lol

 

[BlueSVT]

If I don't warm it up, it has a serious reduction in power when it's cold, in the RPM range below 4K it's almost useless... Anybody else experience that? Once warmed up it's fine again, but when the engine is cold I have NO power until 4000+ RPM.

 

[Squatting Dog]

If I don't warm it up, it has a serious reduction in power when it's cold, in the RPM range below 4K it's almost useless... Anybody else experience that? Once warmed up it's fine again, but when the engine is cold I have NO power until 4000+ RPM.

Wondering if it is cai and tunes, since mike dials back richness in his tune. Increased intake velocity and leaner fuel mixture, would cause that..

-Greg

 

[Deinonychus]

Hey fellas, the main reason is air density. Much like when you add forced induction, you need more fuel to compensate for the higher density air charge. Colder air = denser air, so the computer adds more fuel. That's also why a jet aircraft performs significantly better in cold weather. Denser air through the engine.



- YODA

I don't buy the denser air causing poorer gas mileage. Improved performance is more efficient performance. Maybe more fuel for more air, but it isn't wasted. The vehicle runs faster. You don't need to go faster, so you back off to the amount of gas you need to travel "x" miles per hour.

During my test I noticed a distinct change in gas mileage twice a year: at the changes from winter to summer blend and from summer to winter blend.

This year, thus far, without doing a controlled test, but using the computer gas mileage display, at approximately the change from summer blend to winter blend, I was running at 14.4 mpg and shortly thereafter it was reading 14.2 mpg. I then reset the mileage. Today I am at 13.9 mpg.

 

[Squatting Dog]

After an hour of grinding, I was able to clean up the welds. Not perfect, there is light at the end of the tunnel.

Before

After

Before

After

The brown is polishing compound.. Its a promising start.

-Greg

 

[whtrapta]

If I don't warm it up, it has a serious reduction in power when it's cold, in the RPM range below 4K it's almost useless... Anybody else experience that? Once warmed up it's fine again, but when the engine is cold I have NO power until 4000+ RPM.

I have that too. It revs to 4grand before shifting and is just gutless. Its a warm up mode that the truck goes into. When I get on the street at 60 my truck is around 1800 but when its warm the RPMs will suddenly drop to 1600. Pretty cool feature. It will save you from blowing anything with a cold motor