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Q I purchased a new 2012 V6 Ford Escape. The vehicle is just over halfway to the 5,000-mile oil and filter change recommended by the dealer and owner's manual. We do not usually drive more than 8,000 to 10,000 miles per year, and most of our driving is in urban areas. Am I OK with using synthetic oil in the Escape for the upcoming oil change and future oil changes? We keep our vehicles a long time, so I figure any way I can extend the life of an engine is worthwhile. Any thoughts?

A Sounds like a good plan to me. To paraphrase a popular advertisement: Difference in cost of oil change using synthetic oil? $25. Difference in oil change costs per year? $50. Peace of mind from using synthetic oil? Priceless. With two oil and filter changes per year, the additional cost for synthetic oil is nominal and insignificant in the overall total cost of owning, operating, fueling, maintaining, repairing, licensing and depreciating the automobile.

Q I am the original owner of a beautiful garage-kept, dealer-maintained 1996 Honda Accord EX with 115,000 miles. I've had a problem with the engine running rough only when engaged in drive, air conditioning on, and foot on brake. I've replaced motor mounts, timing belt, condenser fan, water pump and belts in the past 5,000 miles. It runs perfectly otherwise. Turning the A/C off eliminates the problem, but the engine shuddering is still obvious. I've been told that "those four-cylinders always shook when A/C is engaged." Any suggestions?

A At this stage of the vehicle's life, I don't think this is a significant problem. It doesn't affect dependability or utility. Having replaced the engine mounts, the only other item I would check would be the vacuum system for the power brake booster. A leak or low engine vacuum at idle due to age and mileage would certainly amplify the roughness. A cylinder balance test might identify a somewhat weak cylinder as a contributing factor. Regardless, I'd be very hesitant to spend any serious money on additional diagnostics or repairs.

Q My problem is a low brake pedal on my 2008 Ford F-150. I have had the brakes bled; no help. I can press the pedal down and hold it while I start the engine and then release it. This brings the pedal up a little, but not where it should be. Within a few days it's back down again. There are no leaks that I can find. I thought about adjusting the rod between the booster and the master cylinder, but I will wait for an answer from you.

A I don't think the master cylinder pushrod is mechanically adjustable, so I can't recommend trying to modify it. Start by making sure the master cylinder bolts aren't loose or the firewall flexing under brake pressure -- either would contribute the sense of a low pedal. Secondly, it may be worth having the dealer or shop bleed the hydraulic control unit for the antilock braking system. This requires a scan tool to actually operate the solenoid valves in the HCU to expel any trapped air. If this restores pedal height but it eventually fades again, the HCU is suspect. To test the master cylinder itself, disconnect, plug and bleed the two outlet ports, apply pedal pressure and see if the pedal still drops lower than it should. If so, the master cylinder is the likely suspect.

Q Can I put a half-gallon of leftover oil-gas mix from my chainsaw into a full tank of gas my car?

A Yes. Assuming a 32-to-1 mix, that would be about 2 ounces of two-cycle oil in perhaps 15 gallons of gasoline -- roughly a 1,000-to-1 mix ratio. No harm, no foul. Consider it a small dose of upper cylinder lubricant.