How To Find The Right Gas For Your Car

Posted on March 21, 2018

auto repair in NHWe all want to find ways to save money at the pump. For many of us, that means we use the lowest grade unleaded gasoline if our car can handle it. While this is the cheapest option, it is important that you consider the needs of your vehicle over the needs of your wallet. Your wallet will thank you later when you don’t need any auto repair in NH for having the wrong fuel. Consider, for example, a Mack truck trying to run on regular unleaded gasoline. It wouldn’t happen. Your mechanics at Gurney’s Automotive are here to help break down how you can tell what gas you need to put into your car.

The Basics

There are three basic things you see when you pull up to the pump: gasoline, ethanol, and diesel. These three things are a part of what helps us get from point A to point B in comfort.


When it comes to gas, the numbers that you see stand for the ability to avoid engine knocking. So 85-87, the lowest grade, will have the lowest capability, since numbers rise as you go up in quality. Gasoline is derived from crude oil and is a mixture.


Ethanol is a biofuel additive added to the gas to try to stretch the supply. It is a form of alcohol derived from corn and most of the time, there is only about 10% of ethanol in the gasoline that we use. The thing about ethanol is that it is a renewable energy source that can be less pollutive than gas – but can also be dirtier.


Diesel also comes from crude oil, and the main difference is how it starts the engine. There are a lot of particles that originate from a diesel exhaust, which explains the black smoke. However, there have been efforts to reduce the sulfur in diesel, which contributes to the price.

Checking your fuel

The best way to check which fuel to use is to look around your gas tank. Usually, it will tell you what you should be putting into the engine. Should it not state it directly in the tank, then your owner’s manual is the next best place to look. It is important to know that should you swap out diesel for gas and vice-versa. Your car will not start. Due to how engines rev up, it is important that the right fuel gets used at all times.

As for the gas grades, these can usually be interchangeable. The only way that it wouldn’t be is if your car calls for a particular category. Many exotic or performance cars require premium gas and will not run well if they do not have it. When it is recommended, you can switch out to a lower quality, but you may not have the efficiency that you would have with the recommended grade. As for going higher in grade, it will not always show better results. Still, it is not going to harm your car.

When it comes to choosing the right gas for your vehicle, you need to consider all factors. Assess the requirements of your vehicle and what you can afford, and always call on Gurney’s Automotive when you need some auto repair in NH!

Sign up to receive our monthly specials & newsletter