Didn't find anything by searching posts. What is the impact on MPG? Thanks.

 

it really depends on your driving style.

- you can get better gas mileage since it doesn't take as much effort to get the car up to speed, but you can get worse mileage if you floor it and drive fast

 

exactly , if you drive the same as before the milegae will be very slightly better but since your car gets faster most people tend to drive a bit faster nulling the effect on gas mileage.

 

The impact on MPG won't be significant enough to justify buying a header just for MPG gains. On 4-1 headers, the increase in power is between mild-high rev points (around 3K-up rpms) Also, with a 4-1, you will lose a very small amount of whp on the low end revs. (between 1-3ish rpms) If you wanted more low-mid power gains with a header, then you would need a 4-2-1. However, they don't make 4-2-1's for the xb yet. There are tons of web sites claiming they have 4-2-1's, but its all 4-1 to my knowledge. (it would be all over the board if a 4-2-1 came out anyway)

In conclusion, you really wouldn't gain any MPG with a 4-1 header. Its almost impossible to increase MPG while increasing WHP.

Cya

 

actually, it is not impossible since it does happen.

 

C'mon Sam, he said almost... Generally speaking, you usually have to find a balance between performance and economy. You give up one to gain the other.

After installing my CAI, I haven't noticed any mpg savings. It feels like I have to use less pedal - 3/4ths vs. to the floor - for some accel moments. I'm driving the same speed (as fast as traffic will allow) and using the same amount of gas but it feels like I'm not working the engine as hard - so go figure....


IMO, the biggest factor on MPG is a weight issue...

Is your foot heavy or light?

I know it's not about a header, but thought it was relevant.

 

you are right, i didn't see the almost.

 

I developed a lead right foot, so I get a tad bit less. I just keep making sure its working in the powerband.

 

I forgive.

Cya

 

will they come out with a 4 -2-1 header. How much more of a difference is it if one made one and what difference is it in moding?

 

The chances of them coming out with a 4-2-1 for the xb specifically is slim to none. Given the lack of room they are working with, it would be extremely hard to make a 4-2-1 header thats 1 piece. They could probably make a two piece, but even then doubtful. I don't have time right now to explain everything, later tonight i will though. Maybe someone else will beat me to it and give you a quicker answer.

Cya