If you've been wondering whether it's time to switch from heating oil to propane — or just trying to figure out whether you're paying a fair price for what you're already using — you're not alone. It's one of the most common questions we hear from Nassau County homeowners, especially after a season with big price swings.
The honest answer is: it depends on numbers most comparison sites never show you. Per-gallon price is only part of the story. What you actually need is a full picture — BTU output, system efficiency, conversion costs, and what local fuel prices actually look like right now in your area. That's what this page is for.
Fuel Cost Comparison: What Heating Oil and Propane Actually Cost Nassau County Homeowners
The number on the pump isn't the whole story. Heating oil delivers roughly 138,500 BTUs per gallon. Propane delivers about 91,500. That means you need approximately 1.5 gallons of propane to produce the same heat as one gallon of oil — so even if propane looks cheaper per gallon, it often isn't cheaper per unit of heat delivered.
As of spring 2026, heating oil prices in Nassau County range from around $4.18 to $4.66 per gallon, with a local median closer to $5.21. Propane prices in the region run higher on a BTU-adjusted basis for most residential customers. When you factor in that Nassau County residents already pay some of the highest electricity rates in the country — around $0.27 per kWh — the economics of switching to any alternative fuel become a lot less obvious than the ads suggest.
How to Compare Fuel Prices the Right Way: BTU-Adjusted Cost, Not Just Price Per Gallon
Here's the calculation most comparison tools skip. To get a true apples-to-apples number, you need to divide the price per gallon by the BTU content, then account for your system's efficiency rating — what the industry calls AFUE, or Annual Fuel Utilization Efficiency.
A modern oil boiler or furnace typically runs at 85 to 90 percent AFUE. A modern propane system can reach 90 to 98 percent. So propane systems do burn slightly more efficiently — but that efficiency advantage rarely closes the gap created by the BTU difference in fuel content. To run the math yourself: take the price per gallon, divide it by the BTU content (138,500 for oil, 91,500 for propane), then divide again by your system's efficiency rating expressed as a decimal. The result is your cost per usable BTU. Do that for both fuels at current local prices, and you'll have a real comparison — not a marketing one.
One more thing worth knowing: older oil systems, particularly those installed before 1990, can have AFUE ratings as low as 60 percent. If that's what you're working with, upgrading to a modern high-efficiency oil system often delivers more savings than switching fuels entirely — and at a fraction of the cost.
Nassau County's heating load is significant. With approximately 4,746 heating degree days annually, most homes here use between 800 and 1,000 gallons of heating oil per season. At current prices, even a 20-cent-per-gallon difference adds up to $160 to $200 over a full heating season — which is why it's worth doing the math carefully rather than assuming any one fuel is automatically cheaper.
Why Nassau County's Housing Stock Makes This Comparison Different From the Rest of New York
Nassau County isn't just another New York suburb. It's one of the most oil-dependent residential markets in the entire country — roughly 59 percent of Long Island homes heat with oil, compared to less than 9 percent nationally. That's not an accident. It's a direct result of how this county was built.
The post-war housing boom that created communities like Levittown, Massapequa, Merrick, and Bellmore produced hundreds of thousands of single-family homes that were designed around oil heat from the start. Many of those homes have never had access to natural gas service. National Grid's distribution network simply doesn't reach every neighborhood here, and extending a gas main to a home that isn't already connected can cost tens of thousands of dollars on its own — before you've spent a dollar on equipment.
That's the context that most online fuel comparisons miss entirely. When someone in Ohio or New Jersey compares heating oil to natural gas, they're probably comparing two available options. For a lot of Nassau County homeowners, the real choice is between oil and propane — because gas isn't on the table at all.
Propane is delivered by truck, stored in a tank on your property, and available anywhere oil is available. That makes it a legitimate alternative to consider. But the comparison still needs to account for the full cost of switching — not just the ongoing price per gallon.
Oil to Propane Conversion Cost: What Nassau County Homeowners Actually Pay to Switch
The ongoing fuel price comparison only matters if switching fuels is financially viable in the first place. And on Long Island, the upfront cost of converting from oil to propane is substantial enough that it changes the entire calculation.
A full oil-to-propane conversion — covering the new furnace or boiler, propane tank, installation labor, and removal of your existing oil tank — typically runs between $5,000 and $15,000 for a standard Nassau County home. That range is wide because it depends heavily on your home's size, the age and configuration of your existing system, and whether your oil tank is above or below ground. Underground tank removal alone can add $1,500 to $2,000 to the project.
Breaking Down the Real Cost to Switch From Oil to Propane in New York
Let's put some real numbers to it. A propane furnace or boiler runs $2,500 to $7,500 depending on size and efficiency rating. The propane tank itself costs $400 to $2,000 to purchase outright, or you can lease one for $50 to $250 per year — though leasing a tank from a propane supplier often means you're locked into buying fuel from that same supplier, which removes your ability to shop for the best price. Installation labor typically adds another $1,000 to $4,000. If your existing oil tank needs to be decommissioned and removed, budget another $500 to $2,000.
Add it up and you're looking at a realistic range of $5,000 to $15,000 before you've bought a single gallon of propane. For comparison, converting from oil to natural gas in New York runs considerably higher — estimates from Long Island HVAC contractors range from $6,000 to $22,000 for homes that already have gas available on the street, and significantly more if a main extension is required.
Now take that conversion cost and divide it by whatever you'd realistically save per year on fuel. If the BTU-adjusted math shows you'd save $300 per year by switching to propane, a $10,000 conversion takes more than 30 years to pay off. If you save $600 per year, you're still looking at a 16-year payback. Meanwhile, a modern oil heating system installed today can last up to 30 years with proper maintenance — meaning the system you replace might have had a decade or more of useful life left in it.
None of this means switching is always the wrong call. If your oil system is already at end of life and you're replacing it anyway, the incremental cost of switching fuels is lower. But if your system is running well, the case for switching purely on fuel economics is harder to make than most conversion advocates suggest.
Heating Oil Alternatives Worth Knowing About Before You Decide
Propane and natural gas aren't the only alternatives worth understanding. Two others come up regularly in Nassau County conversations: heat pumps and Bioheat.
Heat pumps have gotten a lot of attention from NYSERDA and environmental groups, and modern cold-climate models do work in Long Island winters — they can operate efficiently well below freezing. The problem for Nassau County homeowners specifically is electricity cost. At roughly $0.27 per kilowatt-hour, Long Island has some of the highest residential electricity rates in the country. That rate significantly weakens the economic case for electric heating compared to markets where electricity is cheaper. Heat pumps can still make sense as part of a broader energy upgrade — particularly when paired with solar — but the math requires careful, local-specific analysis rather than national averages.
Bioheat is a different story. It's a blend of conventional heating oil and biodiesel — typically between 5 and 20 percent biodiesel — and it works in any existing oil heating system without modification. No conversion, no new equipment, no upfront cost. Bioheat burns cleaner than standard heating oil, produces fewer emissions, and actually provides better lubrication for heating system components, which can extend equipment life. For Nassau County homeowners who want to reduce their environmental footprint without committing to a costly fuel switch, it's a practical, low-friction option available right now. We offer eco-friendly Bioheat blends as part of our standard product lineup.
The broader point is this: the heating oil alternatives conversation is rarely as simple as "switch and save." Every option involves tradeoffs between upfront cost, ongoing fuel price, system compatibility, and local market conditions. Nassau County's specific combination of high oil-heat dependency, limited gas infrastructure, and high electricity rates makes the analysis here genuinely different from most of the country.
Which Heating Fuel Makes Sense for Your Nassau County Home?
After running the real numbers — BTU-adjusted fuel costs, conversion expenses, system efficiency, and local prices — most Nassau County homeowners land in one of two places: either the math clearly favors staying with oil, or they're replacing an end-of-life system anyway and the incremental cost of switching is worth reconsidering.
What rarely makes sense is switching fuels mid-system-life based on per-gallon price alone, without accounting for the full conversion cost and payback period. And what definitely doesn't make sense is paying more than you need to for the fuel you're already using — whether that's because of automatic delivery premiums, hidden fees, or simply not shopping around. Nassau County oil prices vary by nearly 50 cents per gallon across local suppliers. On a 1,000-gallon heating season, that's a $500 difference.
We've been delivering heating oil to Nassau and Suffolk County homeowners since 1976, and we've had this conversation with a lot of families over the years. If you want a straightforward answer about what makes sense for your home — or just want to know whether you're getting a fair price on your current fuel — OK Petroleum Distribution is a good place to start. Reach us at (631) 321-0549, or place an order online with no contract and no extra fees.
