Which gas station has the best gas mileage?
This is a tough question, because it depends on a number of different factors.
Different oil companies have different additives (anti-foaming agents, methyl alcohol, cleaners, rust inhibitors, fuel stablizers, octane enhancers and light aromatics (such as butane for ease of cold starting in the winter) to name a few). These additives are blended in various ways to help with cold starts, clean burning (for emmissions) upper cylinder lubrication in the engine, etc. They also have slightly different ways of calcualting the octane rating.
You will find that you will get better gas milage in the warmer months compared with the colder months as the cold start additives burn faster, thus you car consumes more gas.
The other big factors are related to the type of vehicle you drive, the age of your vehicle, if it's maintained regularly and the type of driving you do.
As a rule of thumb, a well maintained vehicle with fuel injection, driven consistantly, will return better gas milage, regardless of who's gas you buy; compared with an older, carburated, poorly maintained and short trip driven vehicle.
The best thing I can suggest is to put 4 gallons (16 litres) of gas in your vehicle from Shell, reset the trip odometer, drive 60 miles (100 km), then put another 4 up at say Chevron. Record the number of miles (or kilometers on your trip odometer that you went on the shell gas. Once you've driven another 60 miles repeat the process at another gas station. Assuming your driving route is about the same, you'll have a small comparison of what each of the oil companies returns for gas millage. You will probably see only about a 5% variation.
good luck Malcolm
I say Shell.
I measured how much $ per mile for both Shell and Safeway to see which one is more beneficial regardless of the $/gallon ratio (which would persuade people to use Safeway due to the higher Shell prices), and found that you pay much less per mile on Shell compared to Safeway gas. For example, if you were to spend say $50 on Shell or $50 on Safeway, Shell will give you LESS gas, but MORE miles, therefore more beneficial because it's a less expense overall. While Safeway will give you much more gas for the SAME price, but it won't last nearly as long.
I did the same type of driving while measuring both.
In Australia at least, and probably in other countries as well, the brand of petrol displayed at the service station is not especially relevant as there are limited refineries and the output is shared amongst the brands.
Many refineries make Gasoline (Petrol) for a different Brand Names Formula and dispense it to their trucks to save on the distance it is hauled.
I years past I did a tune up and set the timing to the brand I normally ran. Now that is supposedly done automatically by the cars computers system.
the one with the cheapest gas. seriously speaking though, a gas station is only a symbol of some giant corporation that refines fuel for consumers. what make a particular gas station good is the people than own it and work there. You have gas stations then you have service stations. At a gas station you get gas. at a service station you get service with a smile