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Keystone Outback 300ML

Travel trailerbuilt 2019–22Mixed build tierFindable on the used market
WHAT ONE COSTS
$35,100est. used (2022, 4 yr old)

Sticker was $54,053 in 2021. Out of production since 2022, so the used market is the only way to buy one. Estimate assumes a 2022 unit.

WHAT IT WEIGHS BEHIND YOUR TRUCK
~9,210 lbestimated as towed, for 2 people

dry weight 7,910 lb + fresh water (60 gal, full) 500 lb + propane + battery 200 lb + gear for 2 600 lb. Brochure dry weight omits water, propane, batteries and your gear; this estimate doesn't.

You want a tow rating around10,235 lb (10% margin)
GVWR (the sticker maximum)9,500 lb
Tongue weight, loaded~1,223 lb (13%)
Cargo capacity1,590 lb
WHICH TOW VEHICLES IT FITS: 34 OF 95

Judged the way the app judges: estimated loaded weight against each vehicle's rating less a 10% margin, per model year, because the 300ML's published weights changed mid-run.

VEHICLETOW RATINGVERDICT
Chevrolet Silverado / GMC Sierra 1500 (6.2 V8, max tow) '19-2613,300 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax, max tow) '24-2622,500 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '20-2318,510 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '11-1918,100 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '20-2636,000 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '11-1923,300 lbfits, loaded, with 10% margin
Chevrolet Silverado 1500 (max tow) '14-1812,500 lbfits, loaded, with 10% margin
Chevrolet Silverado EV (4WT) '24-2612,500 lbfits, loaded, with 10% margin
Ford F-150 (3.5 EcoBoost, max tow) '24-2613,500 lbfits, loaded, with 10% margin
Ford F-150 (3.5 EcoBoost, max tow) '15-2013,200 lbfits, loaded, with 10% margin
Ford F-150 (3.5 EcoBoost, max tow) '21-2314,000 lbfits, loaded, with 10% margin
Ford F-150 (3.5 EcoBoost, max tow) '11-1411,300 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, gooseneck) '20-2222,800 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, tow pkg) '17-1918,000 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel) '11-1616,600 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 HO diesel, gooseneck) '23-2623,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '17-1932,500 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '20-2237,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '11-1621,600 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2638,000 lbfits, loaded, with 10% margin
Ford F-450 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2640,000 lbfits, loaded, with 10% margin
GMC Sierra EV '24-2612,000 lbfits, loaded, with 10% margin
Nissan Titan XD (Cummins diesel) '16-1912,710 lbfits, loaded, with 10% margin
Ram 1500 (3.0 Hurricane, max tow) '25-2611,610 lbfits, loaded, with 10% margin
Ram 1500 (5.7 Hemi eTorque, max tow) '19-2412,750 lbfits, loaded, with 10% margin
Ram 1500 (5.7 Hemi, max tow) '11-1810,620 lbfits, loaded, with 10% margin
Ram 2500 (6.7 Cummins HO) '19-2620,000 lbfits, loaded, with 10% margin
Ram 2500 (6.7 Cummins) '11-1817,980 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins DRW, gooseneck) '13-1831,210 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '25-2636,610 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '19-2437,090 lbfits, loaded, with 10% margin
Rivian R1T '22-2611,000 lbfits, loaded, with 10% margin
Tesla Cybertruck '24-2611,000 lbfits, loaded, with 10% margin
Toyota Tundra (i-Force Max, tow pkg) '22-2612,000 lbfits, loaded, with 10% margin
The 61it doesn't fit

These verdicts assume 2 people aboard with typical gear. See the margin for your truck and your crew →

THE SPECS
Length34.8 ft
Height (incl. A/C)11.2 ft
Width8.0 ft
GVWR9,500 lb
Dry weight7,910 lb
Dry tongue weight1,050 lb
Cargo capacity1,590 lb
Sleeps6
Slide-outs2
Axles2
Fresh water60 gal
Grey water76 gal
Black water38 gal
Air conditioning15,000 BTU
Awning14 ft

A missing row means the maker never published that figure: unknown, not zero.

WHERE PEOPLE SLEEP
  • 1× front bedroom queen bed(Permanent)—
  • 1× dinette converts to a bed(Convertible)—
HOW IT'S BUILT: 4/5
WallsLaminated fiberglass
FrameAluminum
RoofWalk-on
UnderbellyEnclosed

Keystone (Mixed tier): Keystone RV

YEAR BY YEAR: WHAT CHANGED
YEARSGVWRDRYMSRP
20199,500 lb8,195 lb$54,053
2020–229,500 lb7,910 lb$54,053
  • 2019Introduced
  • 2022Discontinued
FINDING ONE

Findable: a few listed nationwide most weeks. Why: Keystone is a volume manufacturer. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Mid-living room with a kitchen island, two slides.

OTHER OUTBACK FLOORPLANS
17BH · 5,000 lb · sleeps 518BHS · 5,500 lb · sleeps 519RBS · 5,600 lb · sleeps 4210URS · 6,500 lb · sleeps 8212RB · 8,500 lb · sleeps 4221MD · 8,500 lb · sleeps 4221UMD · 7,200 lb · sleeps 6240URS · 7,700 lb · sleeps 8244UBH · 7,670 lb · sleeps 8252RD · 9,500 lb · sleeps 6260UML · 8,200 lb · sleeps 6271FK · 9,500 lb · sleeps 6291BH · 9,800 lb · sleeps 8291UBH · 8,800 lb · sleeps 10the whole line →
Find one for sale

Live listings for the 300ML on the big marketplaces. Each search opens pre-filled with this exact floorplan:

RV Trader ↗Camping World ↗FB Marketplace ↗Google ↗

Inventory varies by site and day. Slim pickings? search the whole Outback line ↗

Is the 300ML your #1, or just a spec sheet?

These are the facts. Whether it beats the other six thousand rigs for you depends on what you care about. Set your priorities as sliders, switch on your hard limits, and watch the whole market re-rank around them. Every exclusion explained, every margin shown.

See where it ranks for you →

Data compiled from manufacturer spec sheets, retrieved 2026-07.