Winter Fuel Blends Explained
Cold weather turns routine fueling into a reliability test. This guide explains how winter diesel blends work, when to use #1 diesel, how anti-gel additives help, what CFPP and cloud point mean, and practical steps to keep fleets, tanks and generators running all winter.
Why diesel “gels” in cold weather
As temperatures drop, wax crystals in diesel begin to form. Enough crystals can clog filters and starve engines. Water in tanks can also freeze and block flow. The fix is a mix of the right winter fuel blend, proper additives, and good tank housekeeping.
#1 vs #2 diesel: what changes and when to blend
- #2 diesel (ULSD #2) is standard for most of the year with higher energy content and better MPG.
- #1 diesel (kerosene/ULSD #1) has fewer waxes and flows better in cold weather, but slightly lower energy content.
Common winter approaches:
- Mild cold: stay with treated #2 plus anti-gel.
- Moderate cold: 70/30 #2/#1 (varies by market).
- Severe cold: 50/50 or higher #1 content, based on operability targets.
Your exact ratio should match local temps, OEM guidance and supplier recommendations. Blending is usually done at the terminal or by suppliers—not at the job site.
Anti-gel additives and how they help
Cold-flow improvers modify wax crystal formation so fuel flows through filters at lower temps. Many winter packages also include:
- De-icers to address dissolved water
- Detergents for injector cleanliness
- Cetane improvers for easier starts
Follow supplier treat rates. Over-treating does not equal better performance.
CFPP, cloud point and pour point explained
- Cloud Point: temperature where wax crystals first appear; fuel looks hazy.
- CFPP (Cold Filter Plugging Point): lowest temperature at which fuel will pass a standardized filter — a practical “will it run” indicator.
- Pour Point: lowest temperature fuel still flows under gravity — typically lower than CFPP.
Target a CFPP comfortably below your lowest expected ambient for the region you operate.
Biodiesel and renewable diesel in winter
- Biodiesel blends (B5–B20) raise the cloud point vs straight ULSD. Many fleets reduce biodiesel percentage in winter or use enhanced additive packages.
- Renewable diesel (RD) often has excellent cold-flow properties and can be a strong winter option where available.
- Always confirm OEM and local spec requirements before changing blends.
Winter readiness checklist for sites and fleets
Tanks and equipment
- Remove water, drain separators and keep caps/gaskets tight
- Replace clogged filters proactively; stock winter-rated spares
- Verify AST/UST fill points are accessible in snow and ice
- Use winterized fuel or additive plan before the first hard freeze
Fleet and operations
- Standardize cold-weather startup procedures and idle limits
- Bundle DEF with diesel deliveries; remember DEF freezes at about 12°F / −11°C but can be re-liquefied without damage
- Train teams on clear vs dyed diesel rules for highway vs off-road equipment
Procurement
- Set regional #1/#2 ratios and additive specs with suppliers
- Stage emergency coverage and lead-time expectations for storms
- Centralize invoices and drop tickets for audit and tax documentation
How Fuel Me automates winter fueling
Fuel Me ties winter planning, automation and control into one platform:
- FuelConnect, Nationwide Vendor Marketplace. Select vetted suppliers that offer the right winter blends in each market.
- FuelIQ, Tank Monitoring and Auto Reordering. Add weather buffers to tank thresholds so orders trigger earlier ahead of cold snaps.
- FuelIntel, Reporting and Visibility. Track winterized fuel usage, exceptions and costs by site or region; export CSV, Excel or PDF.
- FuelControl, Auditing and Reconciliation. OCR on invoices and drop tickets, three-way match to orders and pricing, clean closeout.
- FuelEvent, RFP and Procurement Engine. Rapid response for gel events, supply hiccups and storm delays.
- FuelRescue, Emergency Fueling and Standby. Run competitive events to lock in winter specifications, SLAs and pricing.
- FuelScore, Vendor Compliance and Performance. Monitor insurance, COIs and SLA performance through winter.
Related services to link:
- Bulk Fuel Delivery
- Onsite Tank Fueling
- Mobile Fleet Fueling
- Generator Fueling
FAQs
What winter blend should I run?
It depends on local temperatures and service windows. Many fleets start with treated #2, then move to 70/30 or 50/50 #2/#1 as temperatures drop. Confirm with your supplier and OEM.
Do additives replace the need for #1 diesel?
In mild cold, a quality anti-gel may be enough. In deep cold, you often need both additive and #1/#2 blending.
Will winter fuel hurt MPG?
A higher share of #1 has slightly less energy content, so MPG can dip. The trade-off is reliability in cold weather.
How early should I switch to winter fuel?
Before the first sustained freeze in your region. Many programs switch by region and ramp ratios as winter deepens.
What about biodiesel in winter?
Biodiesel blends raise cloud point. Many fleets reduce blend levels in winter or specify enhanced additive packages. Check OEM and local requirements.
How do I prevent gelling in stored fuel?
Keep water out, maintain filters, use winterized fuel, and set FuelIQ thresholds with weather buffers so tanks refill early before a cold snap.
Can Fuel Me guarantee a specific CFPP?
CFPP depends on product and treatment. We align to your specification through FuelConnect vendors, document deliveries, and audit invoices with FuelControl.
Does DEF freezing damage equipment?
No. DEF can freeze around 12°F/−11°C and re-liquefies. Most systems warm DEF automatically. Keep jugs and totes protected to avoid cracked containers.
