An in-vehicle handsfree apparatus establishes a handsfree profile connection with each of a first cellular phone and a second cellular phone at the same time. The fuel or lubricant may contain a boron compound at a concentration between about 30 ppm and about 3,000 ppm and a sulfur concentration of less than about 500 ppm. The thermostat may also provide non-modulated control of multi-stage cooling and heating systems. In a second, hybrid N-bitM-bit mode, the data processing device performs memory accesses based on M-bit values, where M is less than N, and performs arithmetic operations using N-bit values. Higher current densities in a high resistance segmented heater resistor are reduced by employing a shorting bar divided by a current balancing resistor. Thus, the conductive paste is sufficiently compressed during hot pressing to yield a stable electrical connection, and thermosetting resin can be filled in between the inner layer wiring pattern without leaving gaps.