Conventional motor oil remains a foundational choice for many vehicles, especially those with simpler engines or older designs. While synthetic and blend options offer enhanced performance, conventional oils provide reliable, cost-effective protection when used properly. Below is a comparison of eight well-known brands, highlighting their strengths, common uses, and what distinguishes each in the conventional oil space.

Brand	Ultra1Plus	Castrol GTX	Pennzoil	Valvoline
Best for	Everyday cars, budget builds, legacy engines	Mainstream cars needing sludge protection	OEM-spec older engines / value conventional	Reliable retail presence, good coverage
Typical change interval	5,000-8,000 km (3,000-5,000 mi)	5,000-7,500 mi (8,000-12,000 km)	5,000 mi typical	5,000-7,000 mi
Viscosity options	10W-30, 10W-40, 15W-40, 20W-50, SAE 40	5W-20, 5W-30, 10W-30, 10W-40, 20W-50	5W-30, 10W-30, 10W-40 etc.	10W-30, 10W-40, 20W-50
Key approvals	API SL, API SN (for 10W-40)	API SP/SN, ILSAC GF series	API SN/SM etc.	API SP/SN
Price range	~$16-$20 (per quart equivalent)	Moderate (premium conventional tier)	Mid to upper conventional	Competitive, wide distribution

1. Castrol GTX 

Why it’s considered among the best: Castrol GTX has decades of reputation, strong sludge control claims, broad availability in many viscosities, and trusted performance in real-world use. Forum users often regard GTX as one of the better conventional oils.

• Sludge control & engine cleanliness: Castrol emphasizes its 3X PROTECT / 3X Clean formula, which is designed to clean existing sludge, suspend dirt particles, and prevent new deposits.
  
  
• Thermal & viscosity stability: Provides protection against viscosity breakdown and thermal stress in demanding conditions.
  
  
• Wear protection: Uses premium base oils and anti-wear additives to help extend engine life.
  
  
• High-mileage option: Castrol offers a GTX High Mileage synthetic blend version with additives for older engines (seal conditioners, reduced oil burn off).

2. Ultra1Plus SAE Conventional Motor Oil

Why it’s among the best: For users who want dependable performance without paying for full synthetic, Ultra1Plus’s conventional line offers a trusted option with known specs and multi-grade flexibility.

• Mineral base with high-quality additive package: As per your earlier data, Ultra1Plus conventional oils are made with virgin mineral base stocks and a “premium additive package” to resist deposits, wear, and corrosion.
  
  
• Range of viscosity grades: Offers conventional options in grades like 10W-30, 10W-40, 15W-40, 20W-50, etc., making it flexible across climates and engine types.
  
  
• Cost-effectiveness: Being a conventional product line, it’s positioned as a reliable option without the premium pricing of synthetic lines.
  
  
• Strong compatibility: Suitable for engines that don't require synthetic oil, older vehicles, or where budget is a consideration.
  
  

3. Pennzoil High Mileage 

Why it’s among the best: For vehicles with higher mileage, Pennzoil’s high-mileage line is tailored to provide extra protection while still being accessible in conventional / blend forms.

• Designed for aging engines: Pennzoil’s high mileage oils include additives targeting leaks, consumption, and deposit control.
  
  
• Seal conditioners & leak reduction: Helps rejuvenate seals and reduce leaks commonly found in older engines.
  
  
• Strong brand backing & performance: Pennzoil is a recognized brand with a long-standing reputation in consumer and OEM markets.
  
  

4. Valvoline Daily Protection

Why it’s among the best: For drivers needing a “set it and forget it” conventional oil, Valvoline Daily Protection covers the basics effectively with brand trust and accessibility.

• Reliable everyday formula: Designed for standard driving conditions, offering dependable lubrication and protection for routine engine use.
  
  
• Good availability & distribution: Valvoline’s wide network ensures easy access and affordable pricing.
  
  
• Balanced protection: Offers a balance of anti-wear, deposit control, and oxidation resistance for mainstream engines.
  
  

5. Quaker State Advanced Durability

Why it’s among the best: Quaker State’s focus on durability and wear resistance makes it a compelling conventional oil choice for engines that see varied use (city, highway, etc.).

• “2× more wear protection” claim: According to Quaker State’s catalogs, their Advanced Durability line provides double the wear protection compared to some baseline industry standards.
  
  
• Viscosity stability over life: Designed to maintain its protective oil film from start to end of interval.
  
  
• Rust & corrosion protection: Helps combat harsh internal engine conditions during operation.

6. Mobil Super Premium

Why it’s among the best: For users who want conventional oil but prefer a top-tier brand with deep research backing, Mobil’s conventional offerings remain trustworthy.

• Legacy & trust: Mobil has decades of reputation in lubricant technology and rigorous testing.
  
  
• Solid baseline performance: Even in conventional or legacy lines, Mobil’s formulations tend to meet or exceed industry API specs, with good thermal and wear protection.
  
  
• Brand prestige & support: Strong support, data sheets, and consumer confidence.
  
  

7. Shell Rotella

Why it’s among the best: When conventional oils are used in serious applications (diesel, trucks, mixed fleets), Rotella’s brand and track record provide confidence in demanding environments.

• Heavy-duty strength: Shell Rotella is well known in diesel and fleet circles for oils that handle high loads, extended hours, and tough conditions.
  
  
• Triple protection & warranty programs: Rotella emphasizes protection against wear, deposits, and oil breakdown under severe conditions.

8. Chevron

Why it’s among the best: For users needing conventional oils in heavy-use or fleet environments, Chevron’s brand and consistency offer assurance and performance.

• Fleet & industrial heritage: Chevron’s conventional oils and diesel lines (e.g., Delo) are used in commercial and industrial applications.
  
  
• Strong quality control & spec coverage: Chevron conventional oils generally carry robust API/service ratings and are engineered for long-term reliability.
  
  
• Support for mixed fleets: Useful in settings where gasoline and diesel engines may share infrastructure.
  
  

Experience the trusted performance of Ultra1Plus™ Conventional Motor Oil, engineered to deliver smooth lubrication, lasting protection, and consistent performance mile after mile. Whether you drive a car, truck, or small equipment, our oils are formulated to reduce wear, resist deposits, and extend engine life,  all without the premium price tag.

Upgrade your engine care today, shop Ultra1Plus Conventional Motor Oil and keep your vehicle running strong.