Full-synthetic oil is way to increase gas mileage

Dear Edward: I'm an advocate of full-synthetic fluids and I stock most brands at my shop. As far as brand, they are all good. For the posi-rear differential we use the factory GM synthetic gear oils. The viscosity we use is the same as the factory recommendation for conventional gear oil. You should also change the fluid in the transfer case. If GM recommends a posi additive, then I would use it. The synthetic gear oil, like engine oil, will not thicken when cold and also has less foaming and less drag. All this will help increase gas mileage.

Dear Norman: When removing glue-on decal emblems, or in your case poor quality bumper extensions, you can buy specialty decal and glue remover from most auto parts stores. I suggest using a heat gun or hair dryer to heat up the bumper pieces. The heat helps to soften the glue and makes removal easier. Use decal remover to remove the remaining glue, then use wax to seal the surface.

Dear Michael: The most common issue is faulty starter gear. The noise is the starter gear not meshing with the ring gear on the flywheel, or flex plate. I suggest removing the starter motor and inspecting the teeth on the ring gear. If you replace the starter motor, then use a quality remanufactured starter motor. If you decide to change the starter motor yourself, then you will find one of the three starter bolts may be hard to access. I've also found in some cases the bolts could be frozen in the transmission case and also be difficult to remove.

Dear Jeff: When you shut the engine off and push the VSA button you are resetting the system without knowing the trouble fault code, so it becomes impossible to tell you what is wrong. The good thing about today's vehicles is the computer systems (with the correct scan tool and a qualified technician) can scan the computer for history, pending and live codes. It would be great to have the VSA light on when the car is brought in to check it.

Dear Lou: There is no question that open style rims offer great brake cooling. The fully enclosed rim design with no vent holes or slots will not cause any brake issues -- unless you are racing on a track. -- Junior Damato, Motor Matters

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