The following items must be serviced more frequently on cars normally used under severe driving conditions. Refer to the chart below for the appropriate maintenance intervals.
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.


Severe Driving Conditions
A- Repeatedly driving short distances of less than 5 miles (8 km) in normal temperature or less than 10 miles (16 km) in freezing temperature
B- Extensive engine idling or low speed driving for long distances
C-Driving on rough, dusty, muddy, unpaved, graveled or saltspread roads
D-Driving in areas using salt or other corrosive materials or in very cold weather
E-Driving in sandy areas
F - Driving in heavy traffic area over 90°F (32°C)
G- Driving on uphill, downhill, or mountain road
H-Towing a Trailer, or using a camper, or roof rack
I -Driving as a patrol car, taxi, other commercial use or vehicle towing
J - Driving over 106 mph (170 km/h)
K-Frequently driving in stop-and-go conditions
Normal Maintenance Schedule
Explanation of Scheduled Maintenance ItemsHyundai Elantra AD (2016-2020) Service Manual: Description and Operation
Cruise Control
The cruise control system is engaged by the cruise "ON/OFF"
main switch located on the right-hand side of steering wheel column. The
system has the capability to cruise, coast, accelerate and resume
speed.
It also has a safety interrupt, engaged upon depressing brake or shif ...
Hyundai Elantra AD (2016-2020) Service Manual: Crankshaft Damper Pulley Components and Components Location
Components
1. Crankshaft damper pulley
...