The Generac OHVI Engine Guide

Generac portable and standby generators are manufactured at the Generac Power Systems, Inc. factory in Whitewater, Wisconsin. Their reputation for reliability is second to none. One reason for this is the Generac OHVI engine.

OHVI engine

Air-cooled generators come with engines that use fans to assist engine cooling. Liquid-cooled generators use enclosed radiator systems for cooling, similar to an automobile. Generally, liquid-cooled engines are used on larger KW generators due to the larger engines requirement for higher power output.

Most home emergency generators are equipped with engines that are manufactured primarily for lawn and garden applications. On the other hand, Generac OHVI engines are made specifically for generators. They are engineered to run for long periods of time, which is a huge asset when you are confronted with a severe power outage.

Generac OHVI engines have a significantly longer life than competitive engines – an unprecedented three to four times longer – making them the best investment on the market. In fact, they are designed to provide approximately 3,000 hours of use.

Lawn mower engines have no oil level protection, which means the engine continues to run even when the oil level is low… possibly causing serious damage. The OHVI engine shuts down automatically when the oil level is or overheated oil is detected.

In addition, the OHVI pressurized lubrication system works from start-up to shut-down by pumping oil directly to every critical area. Most competitive models splash oil on moving parts thereby missing critical friction areas.

Generac generators have a full pressure lubrication system to allow for the use of an automotive grade oil filter to remove dirt and carbon solids. This compares with many other engines that have no filter at all and rely only on oil changes to drain out impurities and harmful debris.

Another outstanding feature is Generac’s OHVI X-TorqTM Governor, which is the fastest responding governor available. It maximizes engine performance and virtually eliminates stalling. A slow governor can result in poor, low voltage, potentially damaging the electronics.

The Generac OHVI engine powers all portable generators of the XP SERIES 4000-8000 Watts and the XG SERIES 4000-10000 Watts, as well as the GP7000, GP7000E, GP8000, GP8000E, GP15000E, and GP175000E models.

Here are a couple of these models on amazon:

Generac 7676 GP8000E Portable Generator, Orange, Black

 out of stock
as of November 28, 2023 11:15 pm


  • Featuring power Rush advanced technology – delivers over 30% more starting capacity allowing you to do more with less
  • Dimensions: 27.2" W x 27" D x 26.5 H | Weight: 198 lb
  • 10000 Starting Watts. 8000 Running Watts
  • Electric start Model for easy operation (Battery included)
  • Generac durable OHV engine with splash lubrication provides a long engine life

Generac 5734 GP15000E 15000 Running Watts/22500 Starting Watts Electric Start Gas Powered Portable Generator

$6,199.99  in stock
as of November 28, 2023 11:15 pm


  • Generac 992cc OHVI engine incorporates full pressure lubrication with automotive style spin on oil filter for a longer life engine
  • Electric start with battery (included) and plug-in battery charger jack
  • Hour Meter / Low-oil level shutdown / Idle control reduces noise and conserves fuel
  • 16 gallons fuel tank provides up to 10 hours of run time at 50% load
  • Hardened 1 1/4" steel tube cradle for added durability and strength with an integrated lifting eye for easy transport and security on the jobsite

All current Generac models can be found on Amazon by visiting here >>> Generac Product Page (Amazon)