You've probably seen propane advertised as the cleaner, more efficient alternative to heating oil. Maybe a neighbor in Nassau County switched. Maybe you've been wondering if you're leaving money on the table by sticking with oil. It's a fair question — and it deserves a real answer, not a sales pitch from a company that only sells one of the two.
Here's what we've found after four decades of delivering heating oil to Nassau County and Suffolk County homes: the per-gallon price comparison between fuel oil and propane is almost meaningless without the BTU math behind it. Once you run those numbers, the picture changes considerably.
Cost of Oil vs. Propane: Why the Per-Gallon Price Misleads You
Propane often costs less per gallon than heating oil. That part is true. But a gallon of heating oil contains roughly 138,690 BTUs of energy, while a gallon of propane contains about 91,500 BTUs. In plain terms, you need approximately 1.52 gallons of propane to produce the same amount of heat as one gallon of oil.
So when you see propane priced lower per gallon, you're not comparing equal quantities of heat — you're comparing unequal ones. The only number that actually matters is how many usable BTUs you get for every dollar you spend. That's the BTU-per-dollar calculation, and it's the only honest way to evaluate fuel oil vs. propane for your home.
How to Calculate the Real Cost of Heating Oil vs. Propane
The formula is straightforward: multiply the fuel's BTU content by its equipment efficiency rating, then divide by the price per gallon. The result tells you how much usable heat you're buying for every dollar spent.
For heating oil, a standard system operates at roughly 85% efficiency, which means you're converting about 117,887 BTUs of that 138,690-BTU gallon into actual heat. For propane, modern furnaces can reach up to 98% efficiency, giving you around 89,670 usable BTUs per gallon. Propane's higher equipment efficiency is real — but it doesn't fully close the BTU-per-gallon gap.
Here's where it gets interesting. For propane to match heating oil on a cost-per-BTU basis, its price per gallon would need to stay below roughly 66 cents for every dollar you pay for oil. If oil costs $4.00 per gallon, propane would need to come in under $2.64 to break even on usable heat delivered. When Nassau County propane prices diverge from that ratio — which they frequently do — heating oil becomes the more economical choice.
The Consumer Energy Council of America has called fuel conversion an "expensive gamble" for exactly this reason: the price relationship between the two fuels shifts constantly, and locking yourself into a new system based on today's prices is a risk most Nassau County homeowners don't need to take.
This is the calculation propane marketing never shows you. It's also why we think Nassau County homeowners deserve to see it laid out plainly before they make any decisions about their heating system.
Nassau County's B5 Bioheat® Mandate Changes the Environmental Equation
One of propane's most common selling points is that it burns cleaner than heating oil. In many parts of the country, that argument has some merit. But Nassau County isn't most parts of the country.
New York State requires that all heating oil delivered in Downstate New York — including Nassau County, Suffolk County, New York City, and Westchester — contain at least 5% biodiesel. That means every gallon of heating oil delivered to a Nassau County home is already a renewable-blended fuel, known as B5 Bioheat®. The emissions gap between propane and heating oil in this region is significantly narrower than most homeowners realize, and it's not a choice you have to make — it's built into every delivery by state mandate.
The New York State Energy Research and Development Authority (NYSERDA) and the heating oil dealer association that serves the Nassau County, Suffolk County, and New York City markets both confirm this. If you heat your home with oil in Nassau County, you're already burning a cleaner, lower-emission product than the one your grandparents used — and it works with your existing equipment without any modifications.
This doesn't mean heating oil is perfect from an environmental standpoint. But if the reason you've been considering propane is primarily environmental, it's worth knowing that the product being delivered to your tank right now is not the same as what people picture when they hear "fuel oil." The renewable content in Bioheat® fuel is only going to increase as New York's blending requirements rise over time, which means the environmental case for staying with oil in Nassau County gets stronger every year.
Propane Boiler vs. Oil Boiler: What Nassau County Homeowners Need to Know Before Switching
Nassau County's housing stock tells a story. The ranches, Cape Cods, and split-levels built during the postwar boom of the 1940s through 1960s were designed around oil heat — basement tanks, cast-iron boilers, baseboard radiators. That infrastructure wasn't an afterthought. It was built to last, and in many homes, it still is.
Oil and propane are not interchangeable fuels. You cannot simply switch suppliers and keep your existing equipment. Converting from an oil boiler to a propane system means removing the tank, oil lines, and burner — and replacing them with propane-compatible equipment. According to Angi, that process typically costs between $3,800 and $10,000. That's before your first gallon of propane is delivered.
The Propane Tank Lease: The Part of the Conversation Most Companies Skip
Here's something worth understanding before you sign anything with a propane supplier: in most cases, the propane tank sitting on your property isn't yours. Propane companies frequently own the tanks they install, which means you're leasing the equipment — and that lease comes with a condition most homeowners don't fully register until it's too late.
If the propane company owns your tank, you are required to buy all of your propane exclusively from that company. You cannot call around for better prices. You cannot switch suppliers when rates spike in January. You are locked in at whatever price your supplier sets, for as long as that tank sits on your property.
Compare that to heating oil. Your oil tank belongs to you. If you want to switch suppliers — or shop around for a better price — nothing stops you. No lease. No termination fees. No supplier holding the keys to your fuel supply. That freedom to shop is one of the most underappreciated advantages of staying with heating oil, and it's one that compounds in value every time propane prices climb.
A good basement oil tank can also last more than 30 years. If yours has years of useful life remaining, the math for switching gets even harder to justify. You'd be spending $3,800 to $10,000 to replace a functioning system, then locking yourself into a single supplier relationship, all in pursuit of per-gallon savings that may or may not materialize depending on where prices land in any given Nassau County winter.
We've been delivering heating oil to Nassau County and Suffolk County homes since 1976. We've watched fuel prices move in every direction over four decades, and the customers who've fared best are typically the ones who kept their options open — not the ones who made a permanent equipment change based on a temporary price advantage.
Is It Cheaper to Heat with Propane or Oil? The Honest Answer for Long Island Homes
This is the question most Nassau County homeowners are actually asking, and it deserves a straight answer rather than a hedge.
At any given moment, the cheaper fuel depends on the current price relationship between the two. Because propane contains fewer BTUs per gallon, it needs to be priced at less than roughly two-thirds of the heating oil price to deliver equal heat for equal dollars. When that ratio holds, propane has the cost edge. When it doesn't — and in many Long Island winters, it doesn't — heating oil is the more economical choice.
What the per-gallon comparison almost never accounts for is the full cost picture for someone who is already heating with oil. If your system is running, your tank is in good shape, and you have the freedom to shop heating oil prices across multiple suppliers, the case for converting to propane has to clear a high bar. You'd need to recover the $3,800 to $10,000 conversion cost through fuel savings alone, while also accepting the supplier lock-in that comes with a leased propane tank.
For Nassau County homeowners specifically, there's also the question of what you're comparing propane to. The heating oil being delivered to your home already contains renewable biodiesel under New York's B5 mandate. The efficiency gap between modern oil systems and propane systems is narrower than it was a generation ago. And the flexibility to order on your own terms — whether that's automatic delivery that monitors your usage or a straightforward will-call order with no contract and no extra fees — is something heating oil customers have that many propane customers simply don't.
Is propane ever the right call? Yes — particularly for homes that don't have an existing oil system, or where a full equipment replacement is already necessary for other reasons. But for the typical Nassau County homeowner with a functioning oil boiler and a basement tank that still has years of life in it, the honest answer is that switching to propane is rarely the financial win it's marketed as.
What Nassau County Homeowners Should Actually Do Before Deciding
Run the BTU-per-dollar math with current prices before you do anything else. Compare what you're paying per gallon for heating oil against what propane suppliers in your area are quoting, apply the 1.52-gallon equivalency, and see whether the savings are real or theoretical. Then factor in whether you'd be leasing or owning the propane tank — because that answer changes the long-term picture entirely.
If you're already heating with oil and your system is in reasonable shape, the burden of proof is on propane to justify the switching cost. In most Nassau County scenarios, that burden is harder to meet than the marketing suggests.
We've been delivering heating oil to Nassau County homes for over 40 years. If you want a straight answer about your specific situation — or you're ready to explore heating oil delivery options with no contracts and no lock-in — OK Petroleum Distribution is here to help.
