You got a high heating bill this winter and now you're wondering if propane would have been cheaper. Maybe a neighbor switched. Maybe you've seen the ads. It's a fair question, and you deserve a straight answer — not a pitch.
Here's the thing: the propane vs. oil comparison looks simple on the surface, but it gets complicated fast once you factor in how these fuels actually work, what switching costs in a Nassau County home, and what's changed about heating oil in the last few years. We've been delivering fuel to Long Island homes since 1976, and we've watched a lot of homeowners work through this exact decision. What follows is what we'd tell a neighbor.
Fuel Oil vs. Propane: Why the Per-Gallon Price Comparison Misleads You
When people compare fuel oil and propane, they almost always start with the per-gallon price. That's understandable — it's the number that shows up on your bill. But it's also the number that makes propane look more competitive than it actually is, because a gallon of propane and a gallon of heating oil do not produce the same amount of heat.
Heating oil contains roughly 138,500 BTUs per gallon. Propane contains roughly 91,500 BTUs per gallon. That means it takes about 1.52 gallons of propane to produce the same heat as one gallon of heating oil. Once you account for that, the "cheaper per gallon" math often disappears entirely — especially in New York.
What Does That BTU Difference Actually Mean for Your Heating Bill?
Let's make it concrete. Propane on Long Island is currently running around $3.47 to $3.54 per gallon for delivered residential service. Heating oil is projected to average around $3.50 per gallon for winter 2025. At first glance, propane looks like a wash or even a slight win.
But when you apply the 1.52 gallon ratio — meaning you need 1.52 gallons of propane to match the heat output of one gallon of oil — the effective cost of propane per unit of heat delivered is noticeably higher.
A typical Nassau County home burns somewhere between 800 and 1,200 gallons of heating oil per heating season. To produce that same amount of heat with propane, you'd need roughly 1,200 to 1,800 gallons of propane. Run those numbers at current Long Island propane prices and the annual cost difference is real — and it favors oil.
There's also the seasonal pricing factor that rarely gets mentioned in propane company marketing. Propane prices in the Northeast tend to spike 30 to 80 cents per gallon above summer rates during December through February — which is exactly when your boiler is working hardest. That seasonal surge narrows or eliminates any price advantage precisely when it matters most. Heating oil prices fluctuate too, but you're not starting from a position of needing 52% more volume just to break even.
The bottom line is that comparing fuel costs on a per-gallon basis without adjusting for BTU content is like comparing the price of a 12-ounce coffee to a 20-ounce coffee without noticing the size difference. The number on the label doesn't tell the whole story.
What Switching From Oil to Propane Actually Costs a Nassau County Homeowner
Nassau County's median home was built in 1955. Most of those homes — the Cape Cods in Baldwin, the split-levels in Bellmore, the ranches in Plainview — were built during an era when oil heat was the standard installation across Long Island, and the infrastructure that came with it is still in place. That context matters a lot when you're thinking about switching fuels.
Converting from an oil boiler to a propane boiler isn't a simple swap. Oil and propane systems are not interchangeable — you can't run propane through an oil burner. A full conversion involves decommissioning your existing oil tank, purchasing or leasing a propane tank, replacing the boiler itself, and potentially modifying your venting setup.
Boiler installation in Nassau County typically runs between $4,500 and $9,500 depending on the system and the scope of work involved. That's before you factor in the propane tank.
If you lease a propane tank — which is how most propane customers in the Northeast end up doing it, since roughly 95% of propane tanks are owned by the supplier, not the homeowner — you're looking at annual rental fees and, more importantly, a lock-in arrangement. When the supplier owns the tank, you buy propane from them. You can't call around for a better price, and you can't switch providers without having the tank removed and a new one installed.
For a homeowner in a 70-year-old house who already has oil infrastructure in place, the honest question isn't just "is propane cheaper per BTU?" It's "do the long-term fuel savings — if any — justify the upfront conversion cost and the loss of pricing freedom?" For most Nassau County homeowners at current price levels, the math doesn't support the switch.
Cost of Oil vs. Propane in 2025: The Honest Long Island Comparison
The cost comparison between heating oil and propane is genuinely close right now — closer than it's been in some years — but "close" doesn't mean propane wins. And in New York specifically, there are a few factors that shift the balance back toward oil in ways that don't show up in a simple per-gallon comparison.
New York State now requires all heating oil sold in the state to contain at least 10% biodiesel — a blended fuel called Bioheat. That requirement went into effect July 1, 2025, and it increases to 20% biodiesel by 2030. That's not optional, and it's not a marketing claim. It's state law, and it means every gallon of heating oil we deliver to a Nassau County home today is already a cleaner fuel than what was being burned five years ago.
Is Heating Oil Still a Good Choice in 2025? What Bioheat Changes
One of the most common reasons homeowners consider switching to propane is the perception that oil is dirty or outdated. That perception made more sense a decade ago. Today, it's increasingly out of date — and New York's mandatory Bioheat transition is the reason.
Bioheat is a blend of conventional heating oil and biodiesel derived from renewable sources like soybean oil and recycled cooking grease. At the B10 level now required by New York State, it's already reducing emissions meaningfully. Testing by the National Oilheat Research Alliance shows that B20 — the blend required by 2030 — cuts sulfur oxide emissions by up to 80% and nitrogen oxide emissions by approximately 20% compared to conventional oil.
Critically, Bioheat is a drop-in fuel. No modifications to your boiler, your tank, or your service contract. You're already receiving it with every delivery we make.
Propane does burn cleaner than conventional heating oil at the point of combustion — that's true. But the gap between propane and Bioheat-blended oil is narrowing with every year the state's blending requirements increase. By 2030, when B20 is mandatory across New York, the environmental argument for switching from oil to propane becomes significantly weaker than it is today.
There's also a practical efficiency point worth understanding. Modern high-efficiency propane boilers can reach AFUE ratings of 89 to 98%. High-efficiency oil boilers typically land between 80 and 90% AFUE. That efficiency gap is real, but it's narrower than it sounds once you account for the BTU content difference. A propane boiler running at 98% efficiency is still burning 1.52 gallons of fuel to match the heat output of one gallon of oil at 90% efficiency. The net advantage is smaller than the AFUE numbers alone suggest.
The Freedom to Shop: Why Oil Heat Customers Have an Advantage Most Don't Think About
Here's something that rarely comes up in the propane vs. oil conversation: who owns the tank.
When you heat with oil, you almost certainly own your tank. That means you can call any licensed heating oil supplier in Nassau County, compare prices, and order from whoever offers the best deal that week. No contract required, no penalty for switching, no annual rental fee. That flexibility has real dollar value, especially in a market like Long Island where multiple suppliers compete for your business.
When you heat with propane, the situation is typically the opposite. Because roughly 95% of propane tanks in the Northeast are owned by the propane supplier — not the homeowner — switching providers isn't as simple as making a phone call. The supplier owns the tank sitting on your property, and you're expected to buy propane from them. If you want to switch, you need to arrange for tank removal and a new installation, which is a meaningful logistical and financial hurdle.
We offer both automatic delivery and will-call service — and neither requires a contract. With automatic delivery, our system monitors your usage patterns and schedules deliveries before you run low, so you never have to think about it. With will-call, you control the timing, specify exactly how many gallons you want, and can order and pay online through our system or mobile app. That level of control and transparency is what we think heating fuel delivery should look like.
So Which Boiler Fuel Is Right for Your Long Island Home?
For most Nassau County homeowners with existing oil infrastructure, the honest answer is that switching to propane is unlikely to save you money — and may cost you significantly upfront before you see any return. The BTU math, the conversion costs, the propane tank lock-in, and New York's mandatory Bioheat transition all point in the same direction: heating oil remains the practical, cost-effective choice for the vast majority of Long Island homes in 2025.
That said, every home is different. If your boiler is at the end of its life anyway and you're evaluating your options from scratch, the calculation changes. The right answer depends on your home's existing setup, your usage patterns, and what current pricing looks like when you're ready to make a decision.
If you want to talk through what makes sense for your situation — no pressure, no pitch — OK Petroleum Distribution has been having that conversation with Nassau County homeowners for over 40 years. Give us a call at (631) 321-0549 and we'll give you a straight answer.
