Should I use 85 or 87 gas Colorado?
The short answer is that you should generally use 87 octane gasoline in Colorado. The state's high altitude and lower air density mean that engines in Colorado do not require the higher octane fuel that may be recommended in other parts of the country.
Understanding Octane Ratings and Fuel Requirements
Octane ratings measure a fuel's resistance to premature ignition, or "knocking." Higher octane fuels are less prone to knocking, which can damage an engine. Most passenger vehicles are designed to run on 87 octane regular unleaded gasoline, which is the standard fuel sold at gas stations across the United States.
However, some high-performance or turbocharged vehicles may require higher octane 91 or 93 fuel to prevent knocking. The owner's manual for your specific vehicle will indicate the recommended fuel grade.
The Colorado Difference
Colorado's high altitude, with an average elevation of over 6,000 feet, means the air is less dense. This lower air density reduces the amount of oxygen available for combustion in the engine. As a result, Colorado engines do not experience the same knocking issues as engines at lower elevations, and 87 octane fuel is generally sufficient.
Using a higher octane fuel than recommended in your Colorado vehicle will not provide any additional benefits and will simply cost you more at the pump. The engine is designed to run optimally on the lower octane 87 fuel.
Exceptions and Recommendations
- If your vehicle's owner's manual specifically recommends 91 or 93 octane fuel, you should follow that guidance, even in Colorado.
- Some high-performance or turbocharged vehicles may benefit from using a higher octane fuel to prevent knocking, even in Colorado's high-altitude conditions.
- If you notice any engine knocking or pinging when using 87 octane fuel, you may want to try a higher octane to see if it resolves the issue.
In general, though, 87 octane regular unleaded gasoline is the recommended and most cost-effective fuel for the majority of vehicles operated in Colorado.
Is it OK to use 85 octane instead of 87 in Utah?
Kofford said many owners' manuals are based on cars driving at sea level and Utah is far above sea level. He explained the air is less dense at Utah elevations than at lower altitudes, which means the engine draws in less air during combustion. Up here, 85-octane is just fine for most cars.
What happens if you put E85 gas in an 87 car?
Mistakes involving E85 ethanol
If you accidentally put E85 fuel in a car built for regular petroleum-based gasoline, chances are your check engine light will come on. And while that's never a good feeling, a one-time mistake shouldn't cause engine damage.
Why does Colorado sell 85 octane gas?
The 85-rated gas is made for specific high elevation areas only. This fuel is allowed in high-elevation areas where the barometric pressure is lower, resulting in lower temperatures for combustion. The lower rated fuel could be tolerated by engines that use carburetors.
What gas to get in Colorado?
State Octane Ratings
| State | Regular Unleaded | Premium Unleaded |
|---|---|---|
| Arizona | 87 | 91 |
| Arkansas | 87 | 91/93 |
| California | 87 | 91 |
| Colorado | 85 | 91 |
What cars use 85 gas?
Ford Super Duty F250, F350, F450
| Vehicle | Fuel Type |
|---|---|
| Buick Encore GX FWD 2025 | Ethanol (E85) |
| Buick Envista 2025 | Ethanol (E85) |
| Chevrolet Express 2500/3500 | Ethanol (E85) |
| Chevrolet Silverado 4WD 2025 | Ethanol (E85) |
Do most people use 87 gas?
Regular gas is an 87-octane fuel. Octane ratings measure fuel stability. The higher the octane number, the more stable the fuel. Most cars on the road run on regular gas.
What happens if I use 85 instead of 87?
Potential problems from using 85-octane fuel (such as pinging, power loss, reduced fuel economy, and voiding of the warranty) outweigh the savings from the fuel's lower price.
Should I use 85 or 87 gas in Colorado?
When it comes to which one you should use, McKinley says motorists should fill up their tank with whatever their vehicle manual recommends, often 87-octane.
What cars can use 85 gas?
Ford Super Duty F250, F350, F450
| Vehicle | Fuel Type |
|---|---|
| Buick Envista 2025 | Ethanol (E85) |
| Chevrolet Express 2500/3500 | Ethanol (E85) |
| Chevrolet Silverado 4WD 2025 | Ethanol (E85) |
| Chevrolet Trailblazer FWD 2025 | Ethanol (E85) |
Is 85 octane the same as 87 at altitude?
In most states, regular unleaded is rated slightly higher at 87. In most cases, you won't experience any problems running 85 octane in an ordinary car when a few thousand feet above sea level.
