---
product_id: 317127891
title: "GTX Classic 20W-50 Conventional Motor Oil, 1 Quart, Pack of 6"
brand: "castrol"
price: "$372"
currency: NZD
in_stock: true
reviews_count: 8
category: "Castrol"
url: https://www.desertcart.nz/products/317127891-gtx-classic-20w-50-conventional-motor-oil-1-quart-pack
store_origin: NZ
region: New Zealand
---

# Compatible with gasoline & alcohol-based fuels Thermal degradation resistance under severe conditions High Zinc & Phosphorus for extreme wear protection GTX Classic 20W-50 Conventional Motor Oil, 1 Quart, Pack of 6

**Brand:** castrol
**Price:** $372
**Availability:** ✅ In Stock

## Summary

> 🛠️ Keep your classic engine roaring with Castrol’s legendary protection!

## Quick Answers

- **What is this?** GTX Classic 20W-50 Conventional Motor Oil, 1 Quart, Pack of 6 by castrol
- **How much does it cost?** $372 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/317127891-gtx-classic-20w-50-conventional-motor-oil-1-quart-pack)

## Best For

- castrol enthusiasts

## Why This Product

- Trusted castrol brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Fuel Flexibility:** Seamlessly compatible with both gasoline and alcohol-based fuels for versatile use.
- • **Proven Vintage Power:** Trusted by collectors and racers alike, meeting API SJ standards for classic engines.
- • **Foam-Free Performance:** Minimal foaming ensures consistent lubrication and engine efficiency.
- • **Engine Armor for Classics:** High zinc and phosphorus formula shields vintage engines from wear and metal fatigue.
- • **Unmatched Thermal Stability:** Maintains a tough, thick oil film even under extreme heat and pressure.

## Overview

Castrol GTX Classic 20W-50 is a premium conventional motor oil specially formulated for vintage and performance engines. Its high zinc and phosphorus content provides superior wear protection for push-rod and flat tappet engines, maintaining a durable oil film under extreme conditions. Compatible with gasoline and alcohol fuels, it meets API SJ standards and is favored by classic car enthusiasts for reliable, long-lasting engine care.

## Description

c/collector cars, muscle cars, hot rods and race cars. It’s high zinc and phosphorus content helps prevent premature aging, wear and metal fatigue on engines with high tension valve springs or performance modifications that create high contact pressure and extreme internal temperatures.

Review: good oil, extra ZDDP for older motors - good price, fast delivery
Review: Best stuff for pre-1970 cars. - I use it on my 1960 MGA because of the high zinc content. Delivery was very quick.

## Features

- High Zinc and Phosphorus for extreme wear protection
- Maintains tough and thick oil film even under severe conditions
- Minimal foaming and high resistance to thermal degradation
- Compatible with gasoline and alcohol-based fuels
- Meets or exceeds the following specification: API SJ

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B093RT3B1W |
| Best Sellers Rank | #4,269 in Automotive ( See Top 100 in Automotive ) #76 in Motor Oils |
| Brand | Castrol |
| Brand Name | Castrol |
| Compatible with Vehicle Type | push-rod, flat tappet engines and performance cam applications |
| Container Type | Bottle |
| Customer Reviews | 4.8 out of 5 stars 1,518 Reviews |
| Global Trade Identification Number | 00079191218914 |
| Included Components | Motor Oil |
| Item Type Name | Motor Oil |
| Liquid Volume | 6 Quarts |
| Manufacturer | Castrol |
| Manufacturer Part Number | 15E809 |
| Manufacturer Warranty Description | 12 months |
| Package Information | Bottle |
| UPC | 079191218914 |
| Unit Count | 192.0 Fluid Ounces |
| Vehicle Service Type | push-rod, flat tappet engines and performance cam applications |
| Viscosity | 20W-50 SAE Grade |

## Product Details

- **Brand:** Castrol
- **Liquid Volume:** 6 Quarts
- **Package Information:** Bottle
- **Vehicle Service Type:** push-rod, flat tappet engines and performance cam applications
- **Viscosity:** 20W-50 SAE Grade

## Images

![GTX Classic 20W-50 Conventional Motor Oil, 1 Quart, Pack of 6 - Image 1](https://m.media-amazon.com/images/I/61CUc-w3baL.jpg)

## Questions & Answers

**Q: How much zinc ppm?**
A: Castrol GTX Classic 20W-50 contains a typical Zinc level of 1310 ppm and a typical Phosphorus level of 1199 ppm.

**Q: Is this good with a turbo car, Will this oil work well with a 86 Buick turbo car with no catalytic converter**
A: Just my opinion but with a turbo spinning 80k rpm I would be hesitant using 20w50. I would use a lighter weight like 10w40 or less. If you didn't have a turbo I would say it would be fine because you don't have a catalytic converter to foul up.

**Q: Can this be used for a air cooled 1970 vw beetle?**
A: Thank you for contacting Castrol North America.
Castrol GTX Classic 20W-50 is specially formulated to provide unsurpassed wear protection for classic and collector cars as well as racing applications.
Castrol GTX Classic 20W-50 is a new high-performance conventional oil formula for push-rod, flat tappet engines, and performance cam applications.  It’s blended with high zinc (1400 ppm) and phosphorus content to help prevent premature aging, wear, and metal fatigue on engines with high tension valve springs or performance modifications that create high contact pressure and extreme internal temperatures.  Specially formulated engine oil for classic/collector cars, muscle cars, hot rods, and race cars.
Castrol GTX Classic 20W-50 is suitable for use in automotive gasoline engines where the manufacturer recommends an API SJ or earlier specification 20W-50 lubricant.
NOTE: NOT FOR USE IN MODERN ENGINES WITH CATALYTIC CONVERTERS OR WET CLUTCH APPLICATIONS.
Thank you again for contacting Castrol, we value your patronage!

Castrol Consumer Relations

**Q: What are your thoughts on using this in mowers, generators and pressure washers where a 20W-50 is acceptable?**
A: Castrol GTX Classic 20W-50 is a conventional four-stroke motor oil that can be used in applications calling for a 20W-50 motor oil with an API rating of SJ or prior as long as the application it is used in should not use motor oil with high zinc content.  This formula should not be used in modern engines with catalytic converters or wet clutch applications.

## Customer Reviews

### ⭐⭐⭐⭐⭐ good oil, extra ZDDP for older motors
*by D***S on January 11, 2026*

good price, fast delivery

### ⭐⭐⭐⭐⭐ Best stuff for pre-1970 cars.
*by 4***S on January 9, 2026*

I use it on my 1960 MGA because of the high zinc content. Delivery was very quick.

### ⭐⭐⭐⭐⭐ Awesome Performance – Perfect for Lawn Equipment
*by L***E on July 7, 2025*

I’ve been using Castrol GTX Classic 20W-50 in my lawn equipment, and it’s been absolutely great. It provides solid protection, smooth operation, and helps extend the life of my mower and trimmer. This oil is especially good for older engines or small engines that run hot and need a thicker oil. The only downside is that it’s hard to find in stores, so I usually have to order it online. But when I can get it, it’s worth every penny. If you're maintaining older engines or heavy-duty lawn tools, this oil is a reliable choice. Highly recommended!

## Frequently Bought Together

- Castrol GTX Classic 20W-50 Conventional Motor Oil, 1 Quart, Pack of 6
- Motorcraft FL-1A Oil Filter

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*Product available on Desertcart New Zealand*
*Store origin: NZ*
*Last updated: 2026-02-17*