If you've been told that propane is more efficient than heating oil, you've heard a half-truth. It's the kind of thing that sounds reasonable until you run the actual numbers — and then it gets a lot more complicated.
Most Nassau County homeowners asking this question aren't starting from scratch. They have an existing oil system, an aging burner that might need replacing, and a propane salesperson somewhere in the background telling them now's the time to switch. Before you make a capital decision based on a sales pitch, it's worth understanding what BTUs actually mean, how efficiency ratings factor in, and what the comparison really looks like when you account for where you live and what you're already working with.
BTU of Oil vs. Propane: The Raw Numbers
A BTU — British Thermal Unit — is simply a measure of heat energy. One BTU is the amount of heat needed to raise one pound of water by one degree Fahrenheit. When you're comparing heating fuels, BTUs per gallon tell you how much energy you're actually buying with each delivery.
Heating oil contains 138,690 BTUs per gallon. Propane contains 91,500 BTUs per gallon. That's not a minor difference — it means heating oil carries roughly 51% more energy per gallon than propane does.
To produce the same amount of heat as one gallon of heating oil, you'd need approximately 1.52 gallons of propane. That ratio is the foundation of the entire comparison, and it's the number that tends to get glossed over when someone is trying to sell you a propane conversion.
Propane Versus Oil Heat: Why Price Per Gallon Is the Wrong Comparison
Here's where a lot of Nassau County homeowners get tripped up. Propane often looks cheaper at the pump — or at least competitive with heating oil on a per-gallon basis. But because propane holds significantly less energy per gallon, comparing the two fuels by price per gallon is like comparing a 12-ounce coffee to a 20-ounce coffee by the cup. The container size matters.
The correct framework is cost per million BTUs — meaning, what does it actually cost you to generate a fixed amount of usable heat, regardless of which fuel you're using? When you run that calculation, heating oil's energy density advantage changes the picture substantially.
A useful shortcut: multiply whatever propane costs per gallon by 1.507, and you'll get the equivalent heating oil price you'd need to match it on a pure energy basis. If heating oil is selling for less than that figure in your area, oil is the better value per BTU — full stop.
This matters especially in Nassau County right now. Since 2022, heating oil has been trading at a per-BTU discount to propane across the Northeast, driven by strong global demand for liquefied petroleum gas pushing propane prices higher while distillate markets have remained comparatively softer. That's not a permanent condition, but it's the market environment Nassau County homeowners are actually operating in today.
There's also a supplier dynamic worth understanding. When a propane company installs a tank at your home, they often own that tank — which means you're effectively locked into buying from them at whatever price they set. You can't easily call a competitor for a better rate. We don't operate that way. Our customers can switch suppliers freely, shop around, and negotiate based on current market prices. That flexibility has real dollar value over the life of a heating system, and it's something the per-gallon comparison never captures.
What Nassau County's Older Housing Stock Actually Means for This Decision
A lot of the online comparison articles you'll find treat this as a new-construction decision — as if you're choosing between a brand-new propane furnace and a brand-new oil furnace on a level playing field. That's not the situation most Nassau County homeowners are in.
Much of Nassau County's housing was built during the postwar suburban boom of the late 1940s through the 1970s. Levittown, built starting in 1947, is practically the origin point of that era. Those homes were built with oil heat infrastructure — oil tanks, oil burners, oil boilers — and a large percentage of them still have that infrastructure in place today, either original or upgraded in place over the decades.
If your home is one of them, you're not choosing between two fuels on equal footing. You're choosing between continuing with a system that already exists and paying to install an entirely different one.
Switching from heating oil to propane in a Nassau County home typically means a new furnace or boiler plus propane tank installation — a significant upfront cost that needs to be recovered through fuel savings before the switch makes any financial sense. And given that heating oil has been the better value per BTU in recent years, the payback math often doesn't work out the way the propane pitch suggests it will.
That's not an argument that propane is always the wrong choice. If you're replacing a system that's genuinely at the end of its life and you have specific reasons to prefer propane, the conversion may be worth evaluating carefully. But "my propane rep said I'd save money" isn't a sufficient basis for a decision of that size. The BTU math, the current pricing environment, and the upfront conversion costs all need to be part of that conversation.
Is Propane More Efficient Than Oil? The AFUE Question
This is the claim that gets the most traction in the propane-versus-oil debate, and it's worth addressing directly. Modern propane furnaces can achieve AFUE ratings of 89 to 98 percent — meaning they convert up to 98% of the fuel they burn into usable heat. Modern high-efficiency oil furnaces typically land in the 80 to 90 percent range, with a standard oil boiler running around 87% AFUE.
So yes, on equipment efficiency alone, propane furnaces have an edge. But here's the thing: AFUE only measures how efficiently the equipment converts fuel to heat. It doesn't change the underlying BTU content of the fuel itself, and it doesn't account for what you're paying per BTU delivered.
A 98% efficient propane furnace is still burning a fuel that contains 91,500 BTUs per gallon. An 87% efficient oil furnace is still burning a fuel that contains 138,690 BTUs per gallon. The efficiency gap between the equipment doesn't close the energy density gap between the fuels.
Fuel Oil vs. Propane Cost: Running the Real Numbers
When you factor in both BTU content and equipment efficiency together — which is the only honest way to compare heating costs — the picture becomes clearer. Using New York State's own fuel comparison data as a reference point, fuel oil at $3.00 per gallon with an 87% AFUE furnace delivers useful heat at roughly $24.86 per million BTUs. Propane, at comparable Northeast pricing and even with a higher-efficiency furnace, comes in significantly higher on that same cost-per-million-BTU basis.
You'd need propane's AFUE advantage to be enormous — and the fuel itself to be priced well below heating oil on a per-BTU basis — for propane to win the cost comparison. In the current Northeast market, that combination isn't what most Nassau County homeowners are looking at.
One more thing worth knowing: modern heating oil isn't the same product it was twenty or thirty years ago. Ultra-low-sulfur heating oil and Bioheat® blends — which mix heating oil with biodiesel — burn significantly cleaner than older formulations. We offer eco-friendly heating oil options, including low-sulfur and biofuel-based blends, for Nassau County customers who want cleaner combustion without replacing their entire heating system. The "propane burns cleaner" argument is less clear-cut than it used to be.
The bottom line is that the efficiency story propane marketers tell is accurate in isolation — their equipment does convert fuel more efficiently. But efficiency ratings don't exist in isolation. They exist alongside BTU content, current fuel pricing, and the real-world costs of the system you're actually running. When you put all of those together for a Nassau County home in the current market, heating oil holds up well.
Frequently Asked Questions: Heating Oil vs. Propane for Nassau County Homes
**How much propane would I need to replace my current heating oil usage?**
The answer is straightforward once you know the BTU ratio. For every gallon of heating oil your home currently uses in a season, you'd need approximately 1.52 gallons of propane to produce the same heat output. If your Nassau County home uses 800 gallons of heating oil in a typical winter, you'd need roughly 1,216 gallons of propane to match it. Run that against current propane pricing in your area and you'll have a much more honest picture of what a switch would actually cost you annually.
**What if I run out of heating oil — isn't propane easier to manage?**
This one comes up a lot among Nassau County homeowners who've experienced a run-out, and it's a fair concern. The fuel type isn't what determines reliability — the delivery setup is. We use an automatic delivery program that employs predictive computer models to monitor your consumption and schedule delivery before your tank runs low. You don't have to watch a gauge or remember to call. For customers who prefer more control, our will-call service lets you order exactly the gallons you need, when you need them, online, with no contract and no extra fees. Both options are designed specifically for the way Long Island homeowners actually use their heating systems — including during the cold snaps that hit Nassau County's south shore communities hard when wind off the water drives the effective temperature well below what the thermometer shows.
**Is it worth converting to propane when I replace my furnace?**
The answer depends on your specific situation — your current system, the conversion costs you'd actually face, and the fuel pricing environment at the time you're making the decision. What we'd caution against is making that call based on a single conversation with a propane supplier who has a financial interest in the outcome. The BTU math, the cost-per-million-BTU comparison, and the upfront conversion investment all deserve a clear-eyed look before you commit.
Heating Oil vs. Propane: What Nassau County Homeowners Should Take Away
The short version: heating oil delivers more BTUs per gallon, and at current Northeast pricing, it consistently comes out ahead on cost per unit of useful heat — even accounting for propane's equipment efficiency advantage. For Nassau County homeowners with existing oil infrastructure, the case for switching to propane needs to clear a high bar to make financial sense.
None of this means propane is never the right answer. It means the comparison deserves more rigor than a sales pitch typically provides. Run the BTU numbers, factor in conversion costs, and look at cost per million BTUs — not just price per gallon.
If you have questions about heating oil delivery in Nassau County, NY, or you want to understand your options before making any decisions about your system, we're here. OK Petroleum Distribution has been serving Long Island homeowners since 1976, and straightforward answers are something we've always been willing to give. Reach out to us at (631) 321-0549 or place an order online — no contracts required.
