YETI Rambler 42 oz Straw Mug: problems, parts and running costs

Checked: 2026-10-19

Summary

The trouble with this mug is mostly built into its design: the press-fit straw lid leaves a drinking passage open, so the mug leaks when it tips, and the same lid is not meant for hot drinks. Owners also report lids popping out when the silicone gasket has been fitted upside down, chipped handle finish, and straws that break or go missing. Running cost is $0 a year in required consumables, because YETI sells the matching Extra Large Straw Lid for $10, the Large MagSlider Lid for $10 and the L/XL silicone straw pack for $10, so a lid replaced every second year averages about $5 a year. It is a good buy at $30 or less; above $45 the newer YETI 40 oz Travel Straw Mug is the better design, because its lid actually closes.

Common problems and fixes

Leaking when it tips — the Extra Large Straw Lid deliberately leaves a drinking passage open, so liquid comes through and around the straw when the mug is laid down or knocked over; one exact-model owner reported leakage from a toppled mug and another bought a sliding replacement lid. This is a design limitation rather than a faulty gasket, so keep the mug upright and never pack it sideways in a bag. [1][10][19]
Lid popping out — one owner reported the lid starting to pop out after trouble-free use. The first advice is to check whether the silicone gasket has been reinstalled upside down, and to look for cracks, distortion or debris around the seal; it is a single owner case, not a confirmed production defect. [11]
Chipped handle finish — owners report chipping on the handles of four mugs, and another buyer received two mugs with chipped handles. These are finish and transport anecdotes rather than a failure rate, and cosmetic scratches and normal wear are excluded from the warranty, so inspect a new mug before the first use. [3][12][19]
Straw breaks or goes missing — one owner broke the straw accidentally and another looked for an exact replacement. The $10 Extra Large Straw Lid includes the correct straw and lid assembly, and YETI sells an uncut L/XL silicone straw pack for $10, so you do not have to guess the fit; do not buy the 35 oz “Large” lid for its straw. [4][6][13]
Dents after a drop — the steel shell dents, and a dent could in principle affect the vacuum seal; owners report a mug damaged by rolling out of a vehicle and another with a handle broken off that stayed usable. Accidental dents are normally outside warranty coverage, so if you think it is a manufacturing fault, ask YETI before replacing the mug yourself. [3][12]
Heavy when full — 42 US fl oz of water plus the 1.72 lb empty weight comes to about 4.46 lb, so a filled mug is awkward to carry and a narrow cupholder may accept the base but not the wide upper rim or the handle. YETI asks for a minimum 3-inch cupholder opening and advises measuring your car. [1][9]
Not for hot drinks — the straw lid is not intended for hot beverages. YETI’s answer is the Large MagSlider Lid for $10, which inhibits splashes but still spills if the mug is upended, so use a closed travel mug if leakproof hot commuting matters. [1][2][5]
The newer Travel lid does not fit — the 42 oz mug uses a press-fit lid while the 40 oz Travel Straw Mug uses a threaded one, so the two lid systems are not interchangeable and owners asked about cross-compatibility after the new model appeared. [14][18]

No published test gives a certified number of hours of cold retention for the 42 oz mug; the one independent controlled test available covers a 20 oz Rambler MagSlider, so treat any hour-count for this mug as unverified. [15]

Parts and consumables

Rambler Extra Large Straw Lid (YETI product ID 21071504618) — $10 direct from YETI (October 2026). YETI states it fits the 42 oz Straw Mug and it comes with the correctly sized straw, so it is the safe replacement when the lid is lost, broken or distorted; no replacement interval is published. [4]
Rambler Replacement Large MagSlider Lid (YETI ID 21070070011) — $10 direct from YETI (October 2026). It fits the 42 oz Straw Mug and is the option if you want a sip opening or want to use the mug for hot drinks, though it is not leakproof; replace it only if it is damaged or you are changing drink style. [5]
Rambler L/XL Silicone Straw Pack — $10 direct from YETI (October 2026) for a pack. YETI says it fits the 42 oz Straw Mug without trimming, it is softer than the supplied hard straw, and it is marked for ages 3+ and not for hot, carbonated or pulpy drinks; replace it when it is damaged or lost, not on a fixed schedule. [6]
Standalone rigid straw — no genuine part number, stock listing or price separate from the $10 lid assembly was found, so the lid is the fit-safe route. [4][13]
Gasket-only replacement — no genuine 42 oz gasket-only SKU or cost was found; reseat and clean the existing gasket before replacing the whole lid. [2][4][11]
Handle, body and vacuum shell — not parts you can replace yourself, and no official replacement handle or vacuum liner was found; a manufacturing fault goes through warranty service instead of a repair. [1][3]

Yearly running cost

$0 a year in required consumables: there is no filter, cartridge, subscription, battery or heating element, and the steel mug is not built around any periodic replacement. Replacement timing follows loss, cracks, staining or poor sealing rather than a schedule, so in an undamaged year the accessory spend is $0. As an illustration only, buying one $10 Extra Large lid every two years works out to about $5 a year, which is not a manufacturer interval or an observed breakage rate. Water, ice and dishwashing costs are not quantified.

When it is a good buy

What US stores charged in October 2026:

YETI US direct — $31.50 promotional for selected 42 oz colors, shown against a $45 regular price. Not every core color qualifies, so the lowest advertised color is not the price to expect elsewhere. [1]
Tractor Supply Co — $45.00 for Seafoam and Ultramarine Violet 42 oz mugs in store-specific listings. [7]
Dick’s Sporting Goods — $28.97 to $34.00 on a promotional assortment of 42 oz colors, against a $45 reference price; the listing price may not apply to every size or color. [8]
REI — lists the exact mug and collects owner feedback, but its page says “This product is not available” and gives no figure to act on. [9]

At $30 or less from a trustworthy seller it is excellent value, $30 to $35 is a good sale, and $35 to $45 is reasonable for the size, the replaceable lid and the five-year limited warranty if a spill-resistant straw design suits you. Above $45, move to the alternatives below.

YETI Rambler 40 oz Travel Straw Mug — $48 direct from YETI (October 2026). It uses a threaded, closed, leakproof lid instead of the open press-on system, so it is the better choice when you carry a full drink in a backpack or move between car and desk where spills are expensive. It holds 2 oz less and its lid does not fit this mug. [14][18]
Stanley Quencher H2.0 FlowState 40 oz — $45 direct from Stanley 1913 (October 2026), with a rotating screw-on splash-resistant cover and an empty weight of about 1.18 lb against the YETI’s 1.72 lb. It is the better choice when carrying weight matters, though the lid should not be treated as leakproof in a bag. [16]
Owala FreeSip 40 oz Tumbler — $44.99 direct from Owala (October 2026) for core colors, advertised by its maker as leakproof with a lockable sip-or-swig spout. It is the better choice if you want a protected mouthpiece instead of an open straw, and individual color inventory varies. [17]