While your oil is changed, the sales associates will offer to change your air filter, perform a transmission fluid change and do a variety of other more profitable services in the hopes of increasing the profit margin.

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My Toyota dealer later informed me that only a dealer can tell how much fluid to refill the transmission with because only they have the special diagnostic equipment (laptop) to do that, and that the dipstick FULL reading isn't accurate.

WSJ: By JONATHAN WELSH

Neglecting coolant, brake, transmission and other fluid services.

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