Service intervals vs. quality

By: CAR magazine

Why do some manufacturers (such as Toyota) implement a short 10 000 km service interval on some models, and other vehicles have 15 000-20 000 km intervals (or even longer)? Does the length of service intervals say something about the quality of the vehicle?

JEFFREY MASINGI
Giyani

Answer: Powertrain engineers establish service intervals during development of a certain product by taking into account usage profile and application. They run specific durability tests – where the oil is analysed – and also extract oil samples during the engine dyno and fleet-vehicle programmes to determine the level of oil contamination.

Many modern vehicles run an oil-quality algorithm in the ECU that is calibrated to determine when an oil change is necessary. The algorithm uses engine speed, load and temperature to predict the degradation of the oil. The algorithm also has a maximum-mileage threshold at which the oil has to be changed.

A manufacturer such as Toyota has historically been conservative with oil-change intervals to preserve its legacy of reliability. We believe there is little correlation between vehicle quality and length of service intervals, although it takes engineering expertise to calibrate an oil-change algorithm effectively.

Related Articles
Gazoo

How to make sense of Toyota’s Gazoo Racing model hierarchy