Quick Answer: The Tiffin Allegro RED 33AA is one of the best value entry-level diesel pushers on the used market, offering a smooth ride, spacious four-slide layout, and strong owner satisfaction, with a few trade-offs around slideout reliability and its single-bathroom design. If you've been shopping for a diesel pusher but don't want to commit to 40 feet of motorhome, the Tiffin Allegro Red 33AA has probably come up in your research. It's one of the most talked-about Class A diesel coaches in the under-$200,000 used market - and for good reason. In this review, we'll cover what makes the 33AA stand out, where it falls short, and who it's actually built for, so you can decide if it belongs on your shortlist.Key TakeawaysThe Tiffin Allegro Red 33AA hits a sweet spot between size, drivability, and diesel performance.The interior layout feels larger than expected thanks to its four-slide design.It is a strong option for buyers moving up from gas Class A motorhomes.The floorplan works well for both couples and small families.Build quality and manufacturer support are consistent highlights.It offers one of the better value propositions in the used diesel pusher market.Browse current listings on Pop Sells to compare options and find the right fit.What Is the Tiffin Allegro Red?The Allegro Red line is Tiffin's entry-level diesel pusher series, and the name tells you exactly what powers it: a Rear Engine Diesel. The "RED" branding isn't just marketing - it signals that you're getting the fuel efficiency and smooth ride of a diesel drivetrain without the six-figure-plus price tag of Tiffin's flagship Phaeton or Zephyr. The 33AA is the smallest floorplan in the Allegro Red lineup, sitting at just over 35 feet with four slide-outs. Think of it as the sweet spot between a gas-powered Class A and a full-size luxury pusher.Pop Sells currently has several Allegro Red 33AA listings across model years, including a 2014 model in Belle Chasse, Louisiana, a 2016 model in Fredericksburg, Texas, and a 2020 model in Suttons Bay, Michigan.Specs at a GlanceThe 33AA has stayed impressively consistent over the years, which makes buying used feel far less risky than with some other diesel pushers. While there have been small upgrades in finishes, tech, and performance, the core layout and specs have remained stable from around 2014 through 2020.Here's what you can generally expect:Overall length: 35' 2"Interior height: 84" (7 feet)Number of slide-outs: 4Sleeping capacity: 4 to 6 (depending on configuration)Engine: Cummins ISB 6.7L diesel (typically 340 hp, with increased torque on newer models)Transmission: Allison 3000 MH 6-speed automaticChassis: Freightliner rear-engine dieselFuel tank: 100 gallonsFresh water capacity: 90 gallonsGVWR: 29,500 lbsGCWR: 33,000 lbsTowing capacity: Up to 5,000 lbs (dependent on load and model year)The four-slide configuration is what really sets the 33AA apart. With all slides extended, the coach opens up significantly, creating a living space that feels closer to a much larger motorhome. Many owners estimate the usable interior at roughly 320 to 340 square feet, and it consistently feels more spacious in person than the 35-foot footprint suggests.The Floorplan: Bunk Over Cab, Rear BedroomThe 33AA uses a bunk-over-cab layout, which sets it apart from most other 33 to 35-foot diesel pushers on the market. It is one of the main reasons this coach appeals to families who want diesel performance without jumping into a much larger rig.Front Cab: Bunk Over Cab SetupThe front cab area includes the optional drop-down overhead bunk, adding a true extra sleeping space without sacrificing the main living area. It turns the coach from a standard couple's setup into something that can comfortably handle kids or guests.Living Area: Functional and OpenFrom the cab, the layout flows directly into the living area. You get sofa seating on the driver's side with a dinette across from it, creating a balanced, usable space whether you are relaxing or eating. With the slides extended, this area opens up significantly, and it feels much larger than you would expect in a 35-foot coach.Kitchen: Mid-Coach with Panoramic WindowThe mid-coach kitchen is anchored by a panoramic galley window, which is one of those small details that makes a big difference day to day. It brings in a lot of natural light and makes the space feel less confined, especially when cooking or prepping meals.Rear Bedroom: King Bed and StorageAt the back, the rear bedroom comes standard with a king bed, which is not always a given in this size category. You also get a full-size closet and a dedicated TV, making it feel more like a residential setup than a typical RV bedroom.Bathroom: Compact but FunctionalFor a coach this size, the bathroom is adequate but not spacious. It includes a one-piece molded fiberglass shower (roughly 34" x 34") and a single bathroom layout.Unlike the larger 37BA and 38QBA floorplans on the Tiffin Allegro RED page, you do not get a bath-and-a-half configuration here.What Owners Actually SayReviews of the Allegro Red 33AA on RV Insider are largely positive, particularly for model years 2014 through 2020. Several common threads emerge across dozens of reviews:The Driving Experience Gets Consistent PraiseThe driving experience gets consistent praise. Multiple long-term owners describe the Freightliner chassis paired with the Cummins diesel as a noticeably smoother, quieter ride compared to gas Class A coaches. One owner who moved up from a 25-foot gas unit wrote that the difference in comfort during mountain driving was immediately apparent. Fuel economy typically lands in the 8 to 10 mpg range unloaded, which is competitive for a diesel coach this size.The Floor Plan Earns High Marks from Families and CouplesThe floor plan earns high marks from families and couples alike. With all four slides out, the interior feels open and livable. Owners consistently note that guests are surprised by how large it feels inside relative to its street presence. The panoramic kitchen window, residential refrigerator, and included washer/dryer prep (with washer/dryer available as an option) add to the full-timer appeal.Tiffin's Customer Service Reputation Is a DifferentiatorTiffin's customer service reputation is a real differentiator - just one of the reasons why it's a top-selling RV brand. Several reviewers specifically cite Tiffin's Red Bay, Alabama headquarters as a resource they've actually used - driving the coach in for warranty work and leaving impressed. That kind of manufacturer support is worth factoring into your purchase decision, especially on a used unit.Where the 33AA Falls ShortNo coach is perfect, and the 33AA has a few known drawbacks that are worth paying attention to before you buy.Slideout reliability (Schwintek system): Some owners have flagged issues with the Schwintek electric slideout system used on certain model years. This comes up often enough in owner forums to warrant a careful inspection during any pre-purchase walkthrough.Hydraulic upgrade on newer models: The 2021 and newer models shifted to hydraulic slideouts on the larger rooms, which tend to be more robust. Earlier models do not benefit from this upgrade.Single bathroom layout: The 33AA has a single bathroom, which can feel tight for families, especially when compared to larger Allegro Red floorplans that include a bath-and-a-half setup.Who Is the 33AA Built For?The Allegro Red 33AA is an excellent fit for a few specific buyer profiles. Couples who want diesel comfort without the stress of parking a 40-foot coach will appreciate the 33AA's relatively manageable wheelbase and maneuverability - multiple owners note it fits in most national park sites without issue. Families traveling with kids will get value from the optional overhead bunk and the dinette sleeping option, making it capable of sleeping up to six - perfect for family roadtrips. Buyers who want to move from a gas Class A into diesel without a giant price jump will find the used market for this floorplan well-stocked and reasonably priced.If you're a full-timer who needs two bathrooms, or if you regularly travel with more than four adults, you'd be better served looking at the Allegro Red 37BA or the 38QBA, both of which offer a half-bath in addition to the main bathroom and more overall square footage. Pricing on the Used MarketThe used Allegro Red 33AA market is active and well-priced for what you get. Entry-level examples from the 2014-2016 range typically start in the $80,000 to $110,000 neighborhood depending on mileage and condition. Mid-range 2018-2019 examples with moderate miles run $120,000 to $160,000. The 2019 listing on Pop Sells with 13,000 miles was priced at $200,000, reflecting the premium for low-mileage, more recent examples. New MSRP on recent model years climbed to roughly $300,000 and above, making quality used examples a strong value proposition.What to Look for When Buying a Used Tiffin Allegro RED 33AAA used 3AA can be a great buy, but like any diesel coach, a careful inspection makes all the difference.Slideout condition: Check for smooth operation, alignment, and any signs of binding or uneven wear, especially on models with the Schwintek system.Roof seals: Inspect all seams, vents, and edges for cracking or deterioration, as water intrusion is one of the most common and costly RV issues.Tire age: Tires over 5 to 6 years old should be budgeted for replacement regardless of tread, so check the DOT date codes carefully.Leveling system: Test the hydraulic or electric leveling system to ensure it deploys and retracts properly without leaks or error codes.Service records: Look for consistent maintenance history, including engine, transmission, and generator servicing.Water damage: Check ceilings, walls, and basement compartments for staining, soft spots, or musty smells that could indicate past leaks.Electrical systems: Test outlets, inverter, batteries, and control panels to confirm everything is functioning as expected.Professional inspection: A pre-purchase inspection from a certified RV inspector is money well spent on any diesel coach in this price range. Where to Find a Tiffin Allegro Red 33AA for SalePop Sells is one of the best places to shop for a used Allegro Red 33AA because listings come directly from owners - no dealership markup. You can browse the full selection of Allegro Red by Tiffin coaches, which includes multiple 33AA model years as well as the larger 37BA and 38QBA floorplans if you want to compare. For buyers browsing by class, the full Class A inventory on Pop Sells gives you a wide view of what's available at different price points.Frequently Asked QuestionsWhat Engine Does the Tiffin Allegro Red Use?The Allegro Red is powered by a Cummins diesel engine - typically a 340 hp unit on older model years (2014-2018) and a 360 hp unit on 2019 and newer models. Both versions use an Allison 3000 MH 6-speed automatic transmission and sit on a Freightliner rear-engine diesel chassis. This drivetrain combination is widely regarded as one of the most reliable and service-friendly setups available in the Class A diesel market.How Many Slide-Outs Does the Allegro Red 33AA Have?The 33AA has four slide-outs. This is notably generous for a coach in its size class and is one of the main reasons buyers describe the interior as feeling larger than the exterior footprint suggests.Is the Tiffin Allegro Red Good for Full-Time Living?Many owners do live in the Allegro Red full-time, and it's reasonably well-suited for it. The residential refrigerator, king bed, optional washer and dryer, solid surface countertops, and 7-foot interior ceilings all contribute to a livable setup. That said, the 33AA's single bathroom is the main limitation for full-timers traveling as a couple or family. If two bathrooms are a priority, check out the larger Allegro Red floorplans like the 37BA or 38QBA.What Is the Towing Capacity of the Allegro Red 33AA?The 33AA has a GCWR (Gross Combined Weight Rating) of 33,000 lbs and a GVWR of 29,500 lbs. This means the towing allowance is the difference between those two numbers minus your loaded coach weight. Most owners flat-tow a small to mid-size vehicle like a Jeep Wrangler or small SUV without issue. Always confirm your specific model year's tow ratings and weigh your loaded coach before flat-towing.How Does the Allegro Red Compare to the Allegro Red 37BA or 38QBA?The 33AA is the most compact and maneuverable of the Allegro Red floorplans - easier to park, fits in more campsite configurations, and is generally more affordable both new and used. The 37BA and 38QBA offer more square footage, a second half-bath, and additional sleeping configurations, but they're longer and more challenging to navigate in tight spaces. You can compare available models across all Allegro Red floorplans at Pop Sells.What Are Common Problems with the Tiffin Allegro Red?The most frequently reported issue across owner forums involves the slideout mechanisms - particularly the electric Schwintek system used on the vanity slide in some model years. Hydraulic slideout failures have also been reported, though less commonly. Roof seal maintenance is important on any Class A, and leveling system issues have been noted on some units. None of these are dealbreakers, but they're worth a thorough pre-purchase inspection.