What do you think about a crank scraper for FE?
 

oR do you even know what they are, they bolt to the main caps on the crankshaft sometimes or right to the oil pan bolts, they stop the spray of oil that flies off of the crank while it spins. Has been proven to increase horsepower and FE over time, reduces parasidic loss. My quesion is for 30.00 bucks would you do it? it would go onto a 95 jeep cherokee 4.0 I6

here is the website

Crank Scraper

Typically these things are only effective under hard acceleration, and if thats the case your fuel economy is out the window anyway. They provide no benefit under cruising conditions. I suppose they might have some benefit if you go up very steep hills a lot but thats it.

Or, you can run 1/2 qt low on your oil to keep the crank counter wts from splashing into the oil. I do this on the cars I race and they are a tiny bit quicker AND helps eliminate oil foaming.

Its not worth it for the low rpm driving that you should be at while driving for FE. Run a bit lower on oil like ATaylorRacing said and you'll get even better results.

The only person I know of who's running a scraper is CoyoteX. It's one of those things you can't easily quantify (at least not A-B-A anyway).

If I may make a correction (albeit trivial ;)), I believe it is a windage tray, not a crank scraper, however they are similar in function.

I have a crank scraper and a windage tray on my car :)

Never been able to show an improvement as a result of it, so I always say if you have the oil pan off it is cheap and one of those things that can't hurt but it is really not worth the effort to do unless you are already in the motor doing work.

The theory behind them is decent. The tiny oil drops hitting the spinning crank take energy away from the rotation, but in reality at under 3000 rpms there just isn't enough stuff splattering around to matter. You might get a 0.01% increase in efficiency at low rpms.

yea i got ya, if the oil pan was leaking i would do it, but i guess ill wait for the day

The 4.0 doesn't spin high enough for a scraper to be any help. Plus the main brace girdle more or less does the same thing. Not sure if yours had that or that was part of the 00-02 updates

Actually its not there to prevent drops from hitting the crank. Its there to keep oil sloshing up from the pan from hitting the crank. Preventing drops from hitting the crank is futile because the drops come from the main and rod bearings. Some of this leakage is necessary to splatter some oil on the cylinder walls to provide lubrication to the rings.