The color of gasoline should only matter if you’re flushing an old system, filling up using a jerry can, or suspect someone is selling illegal fuel.
Gasoline should always be a yellow/green translucent color.
Usually, there’s no need to check. However, if you notice that your “gas” is any other color, you should put it to one side. Dispose of it legally and use some fresh fuel from a good gas station.
This guide will tell you what color gas should be and what might be wrong if you notice anything different.
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What Color Should Gasoline Be?
Commercially-available gasoline should have a slight yellowish hue. Some might describe it as closer to green or orange (in certain lighting).
With other colors reflecting around it, it can appear brown or red. It shouldn’t be.
As a refined product before any treatment, it’s either clear or with a slight yellow tinge. Any fuel without particular dyes is known as “Clear” or “White” fuel.
If your gas is any color other than this (or red/brown), it’s probably not gasoline. This guide will address a few myths about this topic.
Myths Around Gasoline Color
This video from ChrisFix is the most comprehensive myth-buster out there. It’s well worth a watch.
Is gas blue? No, it shouldn’t be.
Is my car’s gas red, then? No – again, it shouldn’t be.
Is commercially-available regular gasoline any other color other than that yellow tint mentioned? No!
All gas is the same color: slightly yellow.
Confusion around this topic comes from the different colors used on the grade labels at the pump. In the US, standard fuel is 87 octane. These ratings run up to 94 octane – premium gas.
The labels for these different octane ratings can be different colors, but the fuel itself is always the same.
Old fuels that have sat in storage for a long time may turn a little brown. That’s the only change you’ll ever notice.
What Are The Laws Surrounding Gasoline Color?
There don’t seem to be any specific laws on the color of commercial gasoline. However, it’s always a slight yellow/green color. This comes straight from the refinery.
The most essential fuel dye law in the US surrounds the color red. See below for more information.
In Canada, off-road fuels (red, as below) can also be purple.
Why Is My Gasoline Red?
If you’re looking at your fuel in a red plastic jerry can, you might just be seeing the light reflecting off it.
Alternatively, it could be old fuel and need flushing out before you use it.
If your fuel is genuinely red and fresh, it’s illegal to use in your road car.
Usually, it’s diesel rather than gasoline that’s colored red. Red dyes are added to fuels in the US (and in many countries worldwide) to signify that they’re for off-road use.
These are broadly the same as standard fuels, although they might have a higher sulfur content. Using them in a road car is illegal since they’re subject to lower taxes, which enable off-road industries like construction, agricultural, and marine businesses to stay afloat.
You’ll be severely fined for tax evasion if caught with red-dyed fuel in your car.
If someone else has filled your car with this fuel, you should report them to the police or IRS. If you’ve done it intentionally, get it drained immediately. Replace it with standard gas from a gas station.
How Do I Look At The Color Of Gasoline?
Well, there are a couple of ways to look at the color, but first – why?
There’s usually no need at all. Most people roll up to a gas station and insert the nozzle into their car. The gas travels straight through it and into the tank without them ever seeing it.
If you’re buying from any reputable fuel company, your gas will be a normal color. Don’t worry.
Some old fuel filters are clear if you really want to see it. Find it in your car and look through it. Is it yellow? Good.
Another way you could take a look is with a two-stroke engine. If you have a two-stroke weed whacker, chainsaw, or leaf blower and fill it up from a jerry can, bingo!
Get a white plastic funnel and insert it into the tank. (Don’t use the funnel for anything else, now!)
Pour the fuel in. Be careful not to spill any, but you’ll see the color as it enters the tank. Despite the white shade’s influence, it should still be tinged yellow.
Wanting to see the color of your gasoline is understandable if you’re curious. However, it’s really not very interesting. Watch YouTube videos instead. It’s much less hassle.
What’s The Best Way To Identify Gasoline?
First of all, if you’re in a gas station, read the pump labels!
If you’re working with jerry cans, the best way is through the smell. Gasoline looks virtually the same as commercial diesel but has a slightly different scent. That said, if you aren’t familiar with the two, don’t risk it. Putting diesel in a gas engine – or vice versa – will have catastrophic consequences. At best, you’ll need to drain (and flush) the system.
Dispose of old fuel by going to a dump or recycling yard. They’ll direct you to a safe place. It’s illegal to pour it out in a field, by the side of a road, or down a drain. You’ll face a significant fine.
If you often use jerry cans, ensure you clearly label any that contain diesel. It’s safe to assume that the rest hold gasoline. There are no official laws and rules around jerry cans, although many use yellow ones for diesel and red for gas.
Is Old Gas Bad?
As briefly touched on, old gas will eventually turn a reddish brown. You might also see sediment build-up at the bottom if it’s in a jerry can.
This won’t happen over a few weeks. Gasoline should last for around three to six months before it starts breaking down. It’ll still be fine in your engine for a long time after that.
It’s hard to put a specific number on it, but if a car has sat for several years, the fuel might have degraded enough to cause a problem.
When gas gets old, it loses “combustibility”. That is, it doesn’t burn so well. In turn, this will clog up the engine and potentially cause misfires and low power.
It might still start, though. Don’t run it for long.
If you’re coming to start a car that’s been unused for ten years, you should consider flushing the fuel out. You then need to replace it with some fresh gas.
However, if you didn’t use your car through a Covid lockdown – let’s say for three months – there’s nothing to worry about.
Is Premium Gas A Different Color?
It’s not. It’s precisely the same yellow-green as every other type of gas.
On the subject of premium fuel, does your owner’s manual tell you to use it? If so, you must do so. You might feel an instinctive internal resistance to paying more for gas, but it often saves money in the long run.
Most cars are built to run on 87 or 89 octane, especially older models. Look at the recommended octane number in your owner’s manual or on the fuel filler cap’s inside. Do what it says!
It might be worth using premium fuel occasionally. These often contain engine additives that clean the carbon out. This will lead to a slight increase in efficiency and power.
Why not try filling up with premium gas the next two times you fill up? If it makes a difference, great! If not, you haven’t lost much. Some people use premium fuel every two or three times, to reap the benefits of carbon cleaning.
You could insert a carbon cleaning fuel additive every few fill-ups.
What’s The Best Way To Fill My Car Up?
Head to a standard gas station to fill your car up with gas. In the usual way, choose your grade and insert the nozzle into your car’s tank.
There’s absolutely no need to check the color of the gas beforehand. Go about your business as normal. Wait for the pump to automatically click off, et voila.
If you suspect that a company is supplying red fuels, don’t use them. If there’s enough evidence, it might be worth reporting them to the relevant authorities. Don’t get involved, though. It’s not worth it.
Use premium fuel if it’s beneficial. And then drive away. To reinforce the point, there’s no need to check your gas’s color!
If you badly want to see it, watch online videos or fill up your chainsaw.
That’s all for now. Thanks for reading! The takeaway point? Gas has a minor yellowy-green hue. Naturally, though, it’s transparent.