almost. i have noticed some increase before also just by changing. but i don't recall it being 2mpg before. it seems strange to me for this to happen , and for the oil to be good. i mean if you sent it off to be analysed it would probably still be good. it is very expensive but i am considering starting to change my oil at 50%. or maybe 25%. i wish i could find a quality oil that was not so expensive. if i changed at 3000 , that would be every 2 weeks for me.

 

Heck with oil additives I just was my car and pick up 2 MPG and 6 HP. LOL!!

 

Read read and read,,,,then you might find the answer

 

turbonators will give you at least 3mpg if not more.............

 

That's all. It must be more.....I heard you get 2 MPG from a stubby antenna and another 1 MPG for the Chevrolet stickers on the hood and front grill.

 

On the 4cyd. do not use additives. I did Lucas once on a PT and the oil pump starting having problems. Only use oil that is needed. and you should see 300000 miles.
popapina

 

Here is a story that relates to adding things to the oil. Back in 1988... I was working for an Oldsmobile dealer. These slick sales type dudes came in with this fancy new state of the art machine. Well, this machine had a tank with chemicals, most likely seafoam or the likes in nature. It also had 2 hoses and a pump with all kinds of fittings. What you do is get an adapter for the oil fill cap and 1 for the drain plug and connect it to the hoses. then you run this machine and it circulates this fluid through the eng and "clean it out". Needless to say they wanted a REAL OLD DIRTY ENGINE. The got this poor Mexican Porter to bring in his 150K+ Delta 88. Well his engine started knocking a few days later. If you have build up in the engine bearings YOU NEED IT. IT TAKES UP THE CLEARANCE FROM THE WEAR ON THE ENGINE BEARINGS AND COMPONENTS. Keep the oil changed and maintain the vehicle and forget about it!

 

 

I've used Seafoam and Marvel Mystery Oil (not on the HHR yet).

Have had success with Seafoam, but I did not use it in the oil-top end cleaning only through the PVC hose. Blows lots of smoke, seems to run better after the process. I've also used it in the fuel tank.

Marvel has "sprung a leak" on two high mileage engines. Probably cleaned out too much sludge, or weakened a gasket-causing the leak.

 

Have a couple of old cars that are stored for up to five months a year and add a half pint into the crank case every spring and never had any lifter noise.