Thanks for the post - always interested to see how folks accomplish this task. Tractor owners have discussed/debated/argued/fought over what to use for rear wheel ballast for many years now. Rather than stoke those fires, I thought I would use the latest version of ChatGPT (AI), and I asked this question:
"How does using RimGuard compare to using RV antifreeze or windshield washer and water combinations?" It only took seconds before I got this response:
Great question — lots of tractor owners debate RimGuard (beet juice) versus RV antifreeze and windshield washer fluid/water mixes. Each has different long-range implications for weight, freeze protection, safety, cost, and maintenance. Here’s a side-by-side breakdown:
1. Weight (Ballast Value)
RimGuard (beet juice): ~10.7–11.0 lb/gal. Heavier than water, washer fluid, or RV antifreeze, so you get more weight in the same tire volume.
RV Antifreeze (propylene glycol): ~8.3–8.6 lb/gal (similar to water). Much lighter than RimGuard, so you’d need larger tires or more volume to get equivalent weight.
Windshield washer fluid + water: ~7.6–8.0 lb/gal depending on mix. Also lighter, similar to RV antifreeze.

If maximum ballast is your priority, RimGuard wins hands-down.
2. Freeze Protection
RimGuard: Good to about -35°F (manufacturer spec). Works in most U.S./Canada climates.
RV Antifreeze: Usually protects to about -20°F to -50°F, depending on concentration. Very reliable for cold weather.
Washer fluid: Cheap blue washer fluid is generally good to -20°F, some premium types to -25°F. Mixed with water, protection drops proportionally.

In very cold climates (northern tier), RV antifreeze is safest, though RimGuard usually holds up fine unless you’re in Arctic temps.
3. Corrosion & Rim Life
RimGuard: Non-corrosive. Doesn’t attack rims like calcium chloride.
RV Antifreeze: Non-corrosive. Safe for rims and rubber.
Washer fluid: Usually non-corrosive (mostly water + methanol + dye). Generally safe, though cheaper formulations may have additives that are harsher on rubber long-term.

All three are better than calcium chloride. RimGuard and RV antifreeze are most rim-friendly.
4. Safety / Environmental Impact
RimGuard: Non-toxic, biodegradable, safe for livestock, pets, crops. A spill is a sticky mess, but not poisonous.
RV Antifreeze: Propylene glycol is considered “low toxicity,” but not something you’d want in soil or near livestock in quantity.
Washer fluid: Contains methanol, which is toxic to pets, livestock, and people. A leak or spill in a pasture or near animals could be risky.

For farms with animals or kids around, RimGuard is by far the safest.
5. Cost & Availability
RimGuard: Usually $3–4 per gallon installed at a dealer. You pay for the product + service. Not DIY-friendly unless you have the pump setup.
RV Antifreeze: $2–3/gal retail (cheaper in bulk, especially off-season). DIY-friendly.
Washer fluid: Cheapest option, sometimes <$2/gal at big box stores. Easy DIY fill.

Washer fluid is cheapest, but RimGuard costs more because of its weight advantage and environmental safety.
6. Practical Maintenance / Long-Range Issues
RimGuard:
Heavy → more stress on axles/bearings (true for any ballast).
Can be messy if you ever have to drain it.
Valve stems need to be liquid-rated to avoid clogging/leaks.
RV Antifreeze:
Light → may not provide enough counterweight for loader work.
Easy to top off or replace if a tube fails.
Washer fluid:
Lightest ballast, so often insufficient for heavy work.
Toxicity risk if a tube leaks into a barnyard or field.
Methanol can evaporate slowly through rubber tubes over years, reducing freeze protection.
Bottom Line
If you want maximum weight, long-term rim protection, and farm-safe environmental qualities → RimGuard is best (but higher cost, dealer install).
If you want a cheap, DIY, decent freeze-proof fill and don’t need maximum weight → RV antifreeze is a safer choice than washer fluid.
If you just want something quick and inexpensive, and you don’t have animals around → windshield washer fluid works, but it’s light and carries a toxicity risk.

A good rule of thumb:
Heavy loader work / hilly terrain / livestock nearby → RimGuard.
Moderate work / DIY budget-conscious → RV antifreeze.
Light duty / cheapest option → washer fluid.