AMSOIL Oil Change in San Marcos, TX

About This Service

AMSOIL engine oil change service available in San Marcos. Multiple oil grades and weights available. Get your engine protected by AMSOIL's 100% synthetic formulation that helps fight and protect against engine sludge and deposit contamination for superior long-term engine health.

AMSOIL 100% synthetic motor oil is engineered to outperform conventional and standard synthetic oils in extreme heat, cold starts, and high-load conditions. Its advanced additive package resists oxidation and thermal breakdown far longer than conventional oils, keeping your engine cleaner between changes. As an AMSOIL Authorized Dealer, we stock multiple grades and viscosities to match your engine's exact requirements.

• 100% synthetic formulation for superior protection
• Resists oxidation, sludge, and deposit buildup
• Extended drain intervals available for qualifying vehicles
• Multiple grades and viscosities in stock

At Riley Auto Care & Transmissions, we've been serving drivers in San Marcos and throughout Central Texas since 1978. Our certified technicians use the latest diagnostic equipment and quality parts to get your vehicle back on the road right the first time.

We'll give you an honest assessment and a clear written estimate before any work begins. No surprises — just straightforward service you can trust.