---
product_id: 10622781
title: "Onan OnaMax SAE 15W-40 Engine Oil, 32 oz."
brand: "cummins"
price: "$65.70"
currency: USD
in_stock: true
reviews_count: 8
category: "Cummins"
url: https://www.desertcart.us/products/10622781-onan-onamax-sae-15w-40-engine-oil-32-oz
store_origin: US
region: United States of America
---

# High-temp oxidation resistance SAE 15W-40 viscosity grade 32 oz. precision bottle Onan OnaMax SAE 15W-40 Engine Oil, 32 oz.

**Brand:** cummins
**Price:** $65.70
**Availability:** ✅ In Stock

## Summary

> 🛠️ Keep your Onan generator running like new—because only the best oil makes the cut!

## Quick Answers

- **What is this?** Onan OnaMax SAE 15W-40 Engine Oil, 32 oz. by cummins
- **How much does it cost?** $65.70 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/10622781-onan-onamax-sae-15w-40-engine-oil-32-oz)

## Best For

- cummins enthusiasts

## Why This Product

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

## Key Features

- • **Engine Armor Against Heat:** Formulated to minimize wear from high-temp oil oxidation, keeping your generator running smoother, longer.
- • **Factory-Recommended Quality:** Cummins-approved, the exact oil shipped with every Onan generator for guaranteed compatibility.
- • **Precision Viscosity Control:** SAE 15W-40 grade ensures optimal flow and protection under diverse operating conditions.
- • **Premium Protection in Every Drop:** 32 oz. bottle designed for easy handling and precise refills, reducing waste and mess.
- • **Exclusive Fit for Onan Generators:** Tailored for Onan units—don’t risk your investment with generic oils.

## Overview

Onan OnaMax SAE 15W-40 Engine Oil is a conventional, non-synthetic oil specially engineered to reduce engine wear and oil consumption caused by high temperature oxidation. Factory tested and Cummins-approved, it ensures optimal viscosity and protection for Onan generators, delivered in a convenient 32 oz. bottle.

## Description

Onan OnaMax SAE 15W-40 Engine Oil is factory tested to offer maximum protection. OnaMax Engine Oil is a conventional, non-synthetic oil specially formulated to reduce consumption and engine wear due to high temperature oil oxidation and viscosity increase. All Onan Generators from the factory are shipped with OnaMax 15W-40.

Review: Only use ONAN products on ONAN generators! - One thing I've learned after buying an RV is that the ONAN generators are very particular. I only use ONAN product/parts. This oil is a little pricey but is excellent quality and what ONAN recommends.
Review: Perfect for my RV cummins 7000 generator - Perfect for my RV generator. I don't know why but you can't purchase this product at a automotive store. Only desertcart or Cummins.

## Features

- Conventional non-synthetic oil
- Specially formulated to reduce consumption and engine wear due to high temp oil oxidation
- 32-oz. bottle

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00278MET8 |
| Automotive Fit Type | Universal Fit |
| Best Sellers Rank | #54,268 in Automotive ( See Top 100 in Automotive ) #425 in Motor Oils |
| Brand | Cummins |
| Customer Reviews | 4.8 4.8 out of 5 stars (1,026) |
| Date First Available | August 14, 2012 |
| Global Trade Identification Number | 00690781000704 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 1.92 pounds |
| Item model number | 3265336 |
| Manufacturer | Cummins |
| Manufacturer Part Number | 326-5336 |
| Product Dimensions | 9 x 4.25 x 2.75 inches |
| SAE J300 Viscosity Grade | 15W-40 |
| UPC | 690781000704 |
| Vehicle Service Type | Generator |
| Viscosity | 15W40 sae_grade |

## Product Details

- **Brand:** Cummins
- **Liquid Volume:** 1 Liters
- **Package Information:** Bottle
- **Vehicle Service Type:** Generator
- **Viscosity:** 15W40 sae_grade

## Images

![Onan OnaMax SAE 15W-40 Engine Oil, 32 oz. - Image 1](https://m.media-amazon.com/images/I/61ica2HVebL.jpg)

## Questions & Answers

**Q: Is this for gasoline engines?**
A: This is for Onan gas generators

**Q: Can i use this in a wood chipper with a 4 cycle engine?**
A: If your wood chipper requires 15w 40 weight oil this would most likely meet the motors requirements.

**Q: Why is the price 2x srp?**
A: Yes

**Q: It will work for 2022 Ram 2500 diesel?**
A: Yes.  It makes any diesel fuel become premium diesel.  The 2022 Cummins may not NEED it as much as an older high mileage diesel,  but will still get benefit from it

## Customer Reviews

### ⭐⭐⭐⭐⭐ Only use ONAN products on ONAN generators!
*by J***E on September 5, 2025*

One thing I've learned after buying an RV is that the ONAN generators are very particular. I only use ONAN product/parts. This oil is a little pricey but is excellent quality and what ONAN recommends.

### ⭐⭐⭐⭐⭐ Perfect for my RV cummins 7000 generator
*by D***N on October 15, 2025*

Perfect for my RV generator. I don't know why but you can't purchase this product at a automotive store. Only Amazon or Cummins.

### ⭐⭐⭐⭐⭐ No issues
*by A***R on September 22, 2025*

No issues

## Frequently Bought Together

- CUMMINS NW Cummins 3265336 Onan SAE 15W-40 Oil - 1 Quart
- CUMMINS NW Cummins Onan 122-0836 Oil Filter (Packaging May Vary)
- CUMMINS NW Cummins 1403116 Onan Air Filter

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-03-07*