View Single Post
Old 11-12-2011, 12:21 PM   #238 (permalink)
Master EcoModder
FastPlastic's Avatar
Join Date: May 2008
Location: Ames, IA
Posts: 419

98 Cherokee - '98 Jeep Cherokee
90 day: 17.18 mpg (US)

ZX7R Ninja - '99 Kawasaki ZX7R Ninja
90 day: 42.45 mpg (US)
Thanks: 4
Thanked 13 Times in 12 Posts
Originally Posted by XJguy View Post
4.0L Jeep engines run hot, blocking the grill may not be the best thing to do unless all you do is highway driving and even then it might not be too good an idea. A more permanent but probably more effective way to reduce pressure build up under the hood would be to add air extractors to the hood itself. The added bonus of is that you also reduce front end lift at high speeds keeping the vehicle more stable.
You know, I hear this a lot and I'm not sure I truly believe it. I believe if you go back a ways in this thread we did cover it once upon a time as well.

"4.0L Jeep engines run hot"
That is true. When she's warm she runs a rock solid 209F and she loves it. When it's -10F guess what? Without a block she typically doesn't see 209F before I arrive at my destination of less than 5miles(across town). Highway is actually the only time I found my blocks to be too much. In town driving never exceeds 5miles. I also vary the number of blocks depending on the outside temp.

"add air extractors to the hood itself."
I have seen these, but I'm not sure for starters I could take a saw to my hood, just not my thing. The other reason for the grill blocks is for increased warm-up and to help store the heat between trips. Cut a few holes in the top of the hood and say bye bye to the $$$.

"The added bonus of is that you also reduce front end lift at high speeds keeping the vehicle more stable."
Well, considering I don't pass 60mph I'm not too worried about aero lift.

There are reasons for my madness, one of them is 29.5MPG's highway.

Adjusted for my driving habits. 80%city/20%Highway.
20mpg city/30mpg highway or bust! Check out my mods so far

Last edited by FastPlastic; 11-12-2011 at 01:34 PM..
  Reply With Quote
The Following User Says Thank You to FastPlastic For This Useful Post:
Sven7 (11-24-2011)