Can you explain the principle behind this?

 

When driving with the rear window sealed, it creates drag just like a parachute.

Open the rear and the air passes through instead.

 

Never heard of that. My rear glass won't open anyway. The tail gate keeps it closed.

 

Weird. I had both hard and soft tops and the windows opened.

 

Could lift glass then close gate I suppose

 

Window cracked doesn't apply to jeeps, as all have the rear vent, and has the air flow...

joker----- Sent from my iPhone using JK-Forum

 

Vehicles have had rear vents for decades, for flow-thru ventilation.

 

So then if I am driving down the road and open my ventilation for air to come inside instead of recirculating air inside I lose gas mileage? I think you are drunk on pickle juice. Now I can see losing gas mileage when you remove the lower air dam in front especially if you add an heavy aftermarket bumper.

 

Not referring to you OP, but in many of these threads I see where people put several thousands into tall tires and lifts, steel bumpers and such. Then later are countless threads about getting better MPG with all these mods. Most of them could probably drive 12-15k a year for 5 or 10 years and the increased fuel costs would still not be near what the mods cost.

Taking the airdam off or changing the rake along with lifting it will surely affect MGP. But consider what the long term fuel costs will be compared to what mods cost. Then don't spend too much time worrying about it if you are going to mod a JK.

At least to me worrying about rake or cracking open back windows (?) to increase MPG do not go with the boxy, heavy, inefficent JK (which even in stock form is not very practical) I choose to use as a daily driver.

 

It's not about worrying. It's about being efficient and not inadvertently throwing money away. If one can get better mpg's by some simple procedures, then why not? MOG's matter to me and opening the rear and driving easy make a big difference. One mpg better is about $4 less per fill up. Or a drink at my favorite bar.