This is what we recommend:
Spark Plugs should be changed at 5 years or 54,000 miles
Antifreeze should be changed at 3 years or 36,000 miles
Transmission fluid should be changed at 3 years or 36,000 miles
VLSD fluid should be changed at 3 years or 36,000 miles
Front engine belts should be changed at 3 years or 36,000 miles
Service parts always in stock for the DE and HR