Hi, I am wondering if anyone can help w/ a suggestion to help improve gas mileage on my Mazda pickup. It is a 1998 Mazda B2500 pickup with 5 speed manual transmission, and 171,000 miles. My truck has had all tuneups done (oil, air filter, coolant change, new spark plugs) and some service (new clutch & PP & release bearing, new water pump, new shocks), and is very reliable. It is also in great body shape. My problem is that it gets about 17 miles a gallon, on the freeway. Also, the truck doesn’t have alot of passing power, though it can cruise on the freeway at 75 all day. I am wondering if a bad bearing in the power steering pump could be robbing power from the truck. I noticed when changing the belt, the power steering pump was hard to turn by hand. Also, there is a low whine when the vehicle is running which gets louder when you turn the steering wheel. Could my gas mileage be knocked down from the mid 23 mpg to 17 just because of a bad power steering pump?
Sure it can. Especially at higher RPMs, like freeway driving. The A/C also needs power from the engine, and has been known to take 2-3 mpg from an engine depending on the size of the engine. The smaller engines suffer the worst loss of gas mileage due to less available power to share with the A/C compressor.
Low tire pressure can also kill gas mileage. Check your tires with another gauge and make sure they are at the recommended pressure. There should be a placard in the glove compartment or on the driver’s door post with the proper pressure. 32 psi is a good pressure for most passenger cars and trucks if the pressure is not known.