losing oil

My 99 Ranger with a 4.0 seems to be losing oil. I started out with 5W-30 when I bought it a few months ago and it seemed to run through it. Switched to 10W-40. Same thing. Should I switch back to 5W-30 and use Lucas oil with it? I know Lucas is a great product so I'm just wondering if that might fix the problem. The average loss is about 1/2 quart every 200-300 miles. New valve cover gasket. I don't see any visual smoke any time. Any help is greatly appreciated!

My 99 Ranger with a 4.0 seems to be losing oil. I started out with 5W-30 when I bought it a few months ago and it seemed to run through it. Switched to 10W-40. Same thing. Should I switch back to 5W-30 and use Lucas oil with it? I know Lucas is a great product so I'm just wondering if that might fix the problem. The average loss is about 1/2 quart every 200-300 miles. New valve cover gasket. I don't see any visual smoke any time. Any help is greatly appreciated!nope, it will help for a little bit, but then after the stuff is gone or wears off the leak will be worse.because that kinda of stuff causes gaskets to swell and that causes leak to subside after a bit they shrink, and most times making the leak bigger. it is best to clean the engine of all oil on the outside and check to see if there are any visible leaks

e powers suggestion make sense. It's either leaking or burning oil. Half a quart every 2-300 miles you will surely notice oil spots in your driveway. How is the truck running otherwise? re: performance. Check a couple of your plugs for oil fouling, also your PCV. I also have a '99 Ranger 4.0 and I use the recommended viscosity oil. I'm hardly half a quart low when I'm due for oil change 3-4K miles. Recently

If there is no oil 'slick' on your driveway (that would indicate a leak), you can pull your spark plug to see if there is any oil residue.

If there is you have bad rings on the cylinder or valve seals. If you have blueish smoke from the exhaust that would also indicate oil burning.

The weight of oil only makes a difference with engine and ambient temperatures.