2027 Forest River XLR Boost375BX

The XLR Boost 375BX leaves Forest River's factory at 11,944 lbs dry with 4,676 lbs of cargo capacity. Forest River publishes no GVWR for this line, so the loaded rating is not quoted on this page and is not computed from the other two figures. What the cargo number covers is defined by the factory: fresh water, gear, food, batteries and every dealer-installed accessory come out of it. Fresh water is 8.3 lb per gallon, so filling the 150-gallon fresh tank spends 1,245 lbs of the 4,676 lbs before anything else goes in.

Pin weight is 2,620 lbs, which is 22% of the dry weight. That figure lands on the truck's rear axle and comes straight off its payload rating - not its towing rating, which is the number most often quoted and the wrong one for this decision. Pin weight rises as the trailer is loaded, and a fifth wheel loaded toward its cargo capacity will put substantially more than 2,620 lbs over the bed. Read the payload figure on your own door sticker rather than a brochure maximum for the model.

Tank capacities are 150 gallons fresh, 114 grey and 40 black, 154 gallons of waste capacity against 150 gallons of supply. The ratio is what governs how long the trailer can sit off hookups: waste capacity exceeds fresh, so the fresh tank is the binding constraint and refilling extends the stay. Forest River publishes these three figures per floorplan, and they are the factory's numbers rather than a segment average.

Against the rest of the XLR Boost fifth-wheel roster this is the 2nd of 4 fifth wheels by dry weight, in a line that runs from 9,094 lbs to 13,074 lbs. It sits in the middle of the line by weight. Comparing floorplans inside one line is more reliable than comparing across brands, because every figure here comes from the same factory channel on the same day.

A useful way to read these figures is to stop planning against the dry weight. Nobody tows a trailer at 11,944 lbs: that is the weight before water, batteries, propane, bedding, food, tools and anything the dealer bolted on. Load half the published cargo capacity and this plan is already near 14,282 lbs on the road. Because Forest River publishes no loaded rating for this line, the ceiling has to come from the trailer's own weight label rather than from this page, and the comparison you make against the tow vehicle should use the loaded figure.

Every number above was captured twice from Forest River and checked against itself before it was published. The line listing and the individual floorplan page are two separate factory renderings of the same trailer, and this plan's 4 shared figures agree exactly on both. There is no published GVWR on this line, so the usual arithmetic check - dry plus cargo equals the rating - has nothing to test against here. Where a figure is missing from this page it is because Forest River does not publish it in this channel, not because it was hard to find - and the row says so rather than being quietly dropped.

Forest River publishes no floorplan description for this plan in the channel this page is built from - only the numeric specification block. Rather than describe a layout from the floorplan code, which would be a guess dressed as a fact, this page carries what the factory publishes and says where it stops. 375BX is a XLR Boost designation and this site does not decode it into a layout claim.

How the 375BX differs from the other three XLR Boost fifth wheels. Most distinctive first. Each rank counts only the siblings that publish that field, and a figure most of them share is left out. Not every one of these pages covers the same model years as this one (2027); each figure is the one its own page prints, so a rank compares pages, not one model year.

• Cargo capacity, 4,676 lb: smallest of four; next is the 363BX (4,731 lb).
• Pin weight as a share of dry weight, 21.9%: smallest of four; next is the 286B (23%).
• Length, 45 ft 3 in: longest of four; next is the 366BX (43 ft 6 in).
• Dry weight, 11,944 lb: second-lightest of four, between the 286B (9,094 lb) and the 363BX (12,064 lb).
• Pin weight, 2,620 lb: second-lightest of four, between the 286B (2,090 lb) and the 363BX (2,795 lb).
• Exterior height, 13 ft 5 in: shared with the 363BX; of four, one lower and one taller, nearest the 286B (13 ft 4 in) and the 366BX (13 ft 6 in).

Next to the 286B (2026 page), the nearest lighter floorplan by dry weight, the 375BX is 2,850 lb heavier by dry weight, has 324 lb less cargo capacity, has a pin weight 530 lb heavier, is 13 ft 11 in longer, stands 1 in taller, has a fresh tank 48 gal larger, has a grey tank 6 gal larger and has a black tank 8 gal larger.

Next to the 363BX (2026 page), the nearest heavier floorplan by dry weight, the 375BX is 120 lb lighter by dry weight, has 55 lb less cargo capacity, has a pin weight 175 lb lighter and is 4 ft 9 in longer; the two publish the same exterior height, fresh tank, grey tank and black tank.

Eight 2027 XLR Boost floorplans with a full factory record. They run 6,758 to 13,074 lb dry on lengths of 28 feet 6 inches to 45 feet 3 inches, with hitch weights of 1,175 to 3,220 lb and cargo capacities of 4,072 to 5,300 lb. Forest River publishes no GVWR for these plans in this channel, so none is shown and none is computed.

A full 150-gallon fresh tank is about 1,245 lb of water, 27% of the 375BX’s 4,676 lb cargo capacity, leaving 3,431 lb. Across 4 XLR Boost fifth-wheel floorplans the water share runs 17% to 27%, and this plan’s is the highest. Nearest on that share: XLR Boost 363BX at 26%.

Closest sibling: the XLR Boost 363BX, nearest on the published figures. It differs on 4 of the 7 fields both publish (this plan first): length 45 ft 3 in vs 40 ft 6 in; dry weight 11,944 lb vs 12,064 lb; cargo capacity 4,676 lb vs 4,731 lb; hitch weight 2,620 lb vs 2,795 lb. They match on fresh tank, grey tank and black tank.

Either side of it by dry weight: XLR Boost 286B is 2,850 lb lighter (9,094 lb dry); XLR Boost 363BX is 120 lb heavier (12,064 lb dry).

All 8 XLR Boost floorplans: XLR Boost line hub.

Against the 375BX: the Sabre 33RLP is 4 lb heavier and 6 ft shorter; the Cardinal 35CRIB is 9 lb heavier and 3 ft shorter; the Wildcat 35CRIB is 9 lb heavier and 3 ft shorter.

10 of the 18 fields this catalogue tracks are published for the 375BX. Not published: GVWR, interior height, sleeps, slide count, axle count, tire specification, refrigerator, air conditioning.

Sourcing rules: methodology.