The information available in most of the manuals about what octane gas for Harley needs is very skimpy. Most of the manuals ask you to use unleaded gas which only means that the gas should have the least amount of lead in it. This goes for all kinds of engines as the lead in the gas only helps to add to atmospheric pollution and does nothing else. The lead in the gas does not get burnt but is emitted into the air thus increasing the lead content suspended into the air that everybody breathes in. Hence using unleaded gas is the most common advice you can get.
It is better to take the suggestion of manuals that specify the type of gas with exact octane content needed for the Harley. The manuals which come with the motorcycle are the best ones for reference but in case you did not get one with your Harley bike, then it is better to get one from your local dealer to find out best octane gas for Harley Davidson, which is appropriate for the type of engine your motorcycle has. The Harleys come with different kinds of engines, and the manufacturer is the best person to suggest the kind of gas to be used depending on the compression ratio.
Worrying about the octane content in the gas you are using for the Harley is not applicable to you if you have a supercharged, turbo-charged engine or an engine with ‘nitrous oxide injection. If you are undecided about the type of gas to run your Harley on and are still very confused about what octane gas should I use in my Harley, then perhaps the following information can dispel some of your doubts. You will be able to judge what gas is best for your motorcycle and how you can get the best out of it in the long run from the following.
What Octane Gas should I use in my Harley
The most important factor in choosing the type of gas is the compression ratio of the engine which is either above 10:1 meaning ‘high compression engine’ or below it meaning low compression engine’. This compression ratio usually varies from 11.5:1 to 9.5:1. You may be wondering why this compression ratio is so critical regarding the gas to be used for the Harley. The fact is that the gas octane for Harley in its engine cylinder of the motorcycle has to get ignited for it to expand and provide the power for the movement. Before the gas is ignited it gets compressed by the upward flow in the cylinder.
When the gas gets compressed by the piston, it can also get ignited by the pressure before the spark plug provides the spark to ignite it which is known as ‘pre-ignition.’ This upsets the timing of the piston movement which has to travel some more before the gas should have become ignited by the spark. As a result, the detonation of the gas creates a downward pressure on the piston traveling upwards and is yet to reach its highest point of the trip. The opposing two forces cause the engine to knock and produce pinging noises. It happens mostly during acceleration when more gas is fed into the cylinder to produce more power.
The role of octane in the gas now becomes evident as it can resist this ‘pre-ignition’ detonation. The higher the octane content the higher is the amount of compression that an engine can achieve before the detonation. You can know the percentage of octane content in the gas by the numbers assigned to it which is the proportion. Figures are available for three types octane content such as ‘Regular’, ‘Plus’ and ‘Premium’. For the ‘Regular’ type of gas the figure is 85 to 87, for the ‘Plus’ type it is 88 to 89 and for the ‘ Premium’ type it is 90 to 93.
Lower octane content will help to get more power as it gets ignited quickly but it can cause an imbalance in the engine which can be disastrous for it in the long run. Most of the manufacturers suggest that you use gas with high octane gas in Harley to make sure that the engine does not overheat or cause any knocking when driving your Harley. Another reason behind the manufacturer’s suggestion to use gas with high octane content is to stop the buyer from bringing their Harley in for costly repair which is solvable by a change in the type of gas used.
It is not true that you have to use gas with the highest octane content always which is the biggest misconception that owners of Harleys usually have. Using your ear while driving the motorcycle can be an excellent way to find out whether the type of gas you are using is suitable for your bike or not. If the engine of your Harley knocks or pings too much, just replace the gas in the tank with one having higher octane content and you will feel the difference. Settle on the type that helps your motorcycle to perform the best.
Many owners of Harleys complain that getting gas with high octane content is not possible everywhere in the country. The ‘Premium’ type of gas can give higher compression and power than the ‘Regular’ type, but it also gives lesser mileage. Many places and gas stations all over the country do not sell the ‘Premium’ brand of gas which may worry you. But if these stations are in regions which are higher than other areas such as mountain regions, there is no cause for concern as the compression required at high altitudes is much lower than that needed on the plains.
Even if you are using gas with lower octane content in mountain areas you can always change the situation. While coming down from the high ground, you can quickly alter the gas with a proper one and allow the engine get used to the higher octane content. While traveling to some place, it is better to refer to maps, refer to reviews submitted by other Harley users regarding safe routes and locate the gas stations that sell gas with high octane content. Planning your trip beforehand may save you a lot of trouble and keep your precious Harley safe from damage.
You should always be careful about another thing while using your Harley motorcycle. Always try to avoid octane boosters which are available at various auto stores as much as possible. These boosters do boost the octane percentage in the gas and provide the engine with more power, but it is of a temporary nature only. People who are involved in racing use the octane booster which is supposed to be avoided in normal driving. These boosters do more harm than good which every Harley owner wants to run his motorcycle smoothly for ages should keep in mind. Simply remember that ‘octane boosters’ are for ‘racers.’
The above information will surely provide an answer to what octane gas should I use in my Harley and keep your Harley running for a long time and give you maximum driving satisfaction.
Wish you happy travel with your Harley.