Dynamax DX3 Problems, Fuel Mileage, Review (Helpful Guide)

The DX3 is a powerhouse with its DD8 7.7L 375 HP engine and professional paint job. It will turn heads as the cab is the same design as a tractor-trailer cab. This rig is built with 4-floor plans and between 2 & 3 slide-outs

Not every DX3 is going to have problems. Some owners are lucky and have nothing go wrong. While others suffer cut hoses, lack of flooring support, two different screw heads in the same hinge, and so on. It is the way of RV life.

To learn more about the DX 3, just continue to read our article. It has information on this unique RV design you should know about. Take a few minutes and get caught up on this powerful RV that may go where no other RV can go

Who Makes The Dynamax DX3?


The news may not be good for those RVers who do not like Forest River products. Dynamax who is the maker of the DX 3 RV is a division of Forest River, Inc. It says this on the bottom of their website advertising this RV model.

The DX 3 is selling for a minimum of $378,000 and can get to over $400,000 depending on what luxuries you include in your purchase order. The GVWR is 33,000 pounds and the GCWR is 54,000 pounds for all 4-floor plans.

It comes with a 100-gallon fuel tank and can hold 86 pounds of propane. The freshwater tank holds 94 gallons of water while the gray and black water tanks only hold up to 52 gallons.

All the basic features are included in this model of RV and you can sleep on a nice King sized bed if you like to have lots of room when you go to bed. The 71 by 78-inch bed comes with a gel-infused memory foam mattress for your comfort.

The one issue you have to watch when you buy this RV is its height. At 12 feet 9 inches, it is pushing those clearance levels and you may have trouble on some smaller roads.

How Much is a Dynamax DX3?

This will depend on the floor plan you buy and what optional features you add to the RV. The base price for the 34KD is $378,220 and it reaches 36 feet 8 inches in length.

The 37BD will cost you $385,179 and its length is 39 feet 2 inches. Next is the 37TS and its price tag starts at $391,488 and it is the same length as the 37BD model. The difference between these two models is one slide-out. The 37TS has 3 to the 37BD only has 2.

The final floor plan is the 37RB. Its price tag is $402, 462 and what makes this model different is its 40-foot 9-inch length. It has the same height as the other models as well as the same width.

All four-floor plans come with a 101-inch width. All the tanks and weight capacities are also the same as the other models. Another difference between this expensive model and the others is that it comes with 2 complete bathrooms.

The kitchens are also placed in the same spot on all floor plans. They are near the middle to the front of the RV.

Dynamax DX3 Fuel Mileage


When you come with a Detroit Detroit DD8 7.7L Turbo Diesel Engine that puts out 375 hp and 1,050 lb-ft. of Torque you know you are not going to get great fuel mileage.

This powerful engine is combined with the Allison 3200 6-speed automatic transmission. Even with that help, you can expect to get between 7 and 9 mpg depending on other factors.

This RV is built on a Freightliner® M2 106 Chassis which can hold 33,000 pounds GVWR and 54,000 pounds GCWR. The 100-gallon fuel tank will give you plenty of range and you can travel all day without having to stop for more fuel.

What helps get that range and fuel mileage are the front and rear Michelin® XZE2 275/80R22.5 (14 Ply Radials). These are top tires and much better than those more economical ones you can find at different tire outlets.

The 4.56 Rear Axle Ratio should also help you get excellent gas mileage for an RV of this size. To get you to stop, the company has added the all-wheel ABS air brake system.

There are too many features to list that should help you get top fuel mileage when you drive this bit of beauty.

Common Dynamax DX3 Problems

Common problems are not always as common as you may think. One owner had his Dynamax DX3 for 2 years and never had a problem while other owners suffered from multiple failures and repeated repair times.

But there are some problems you should keep your eye out for:

1. Slide-out fault code- when you push the button to extend or retract your slide-out you may find this error code flashing all the time. Your slide-out won’t move because the fault code is telling you there is not enough voltage getting to the system.

You may have to charge up the batteries some more before the code goes away.

2. Construction problems- it seems that there are more than a few of these models that suffer from this problem. The wall behind the dryer may not be attached to anything and the floor support may only be held together by one screw.

One owner found a crack in his shower and a hole in his washer‘s drain hose that put water everywhere on the floor. Some owners have inferior paint jobs with over-spray issues.

One reason for this inferior quality workmanship is that the company is having a hard time keeping up with the demand.

3. No air pressure to the suspension system- this is caused by a loose U-bolt. This is fixed by tightening it up. You should check your U-bolts every two to three months to make sure they did not get loose again.

4. Bad auto retract system on the awning- this happens to a few owners and it is not really a part you can fix yourself. It is a manufacturing fault as the auto retract will engage at any time without notice.

The only way to fix this problem is to go to your dealer and let them get the right parts They are said to be hard to find on your own.

5. Leaking tanks- this comes from the fitting which may have cracked when someone used a pipe wrench or channel locks to tighten the fitting. If you are under warranty, let the dealer replace the cracked fitting for you

Our Dynamax DX3 Review


This is a very impressive RV> It is called a Super C but it seems to be more on the level of a Class A than a Class C RV. For the price, you get a lot of built-in features that make RV life nice and comfortable.

The interiors look good, well polished, and put together at least at first glance. It is a luxury RV that has the look and feel of a luxury RV, especially with all those built-in features.

We like the power of the engine and with the 3200 transmission, you should be able to climb those mountain roads with relative ease. The 375 HP is also very impressive.

The gas mileage you get is standard and on par with the Class A results. We did not like the exterior look though. The cab is like a tractor-trailer cab and it looks out of place.

You get the feeling you are delivering meat or other products instead of driving a recreational vehicle.

The color combination could be better than it is. At least on the model, we looked at. Its darker purple and gray colors were not that exciting to look at but they may hide the dirt better.

If you can get past the exterior look, this is a fine RV that should be well-built. You are paying a lot of money for this RV so you should get an excellent product as well as a better color combination.

Dynamax DX3 vs Renegade Verona

There are a lot of similarities between these two RV models. They both come with the Freightliner M2 chassis, 4-floor plans as well as measuring 34 to 40 feet in length approx.

The big difference between these two models is that the DX 3 has 375 HP while the Renegade only has an output of 350 HP. The reason for this is their motors. You know the one that is put inside the DX 3.

The Renegade comes with a Cummins L9 that has a two-stage Jake brake built into it. The Renegade will win in the torque comparison. It puts out 1150 lb-ft of torque while the DX 3 engine only puts out 1050.

Both interiors are nice and the difference there will be the color scheme and floor plan. It is hard to say about the construction quality of the Renegade but it is probably similar to the DX 3 construction quality.

Another similarity is that the exterior look and cab design still makes one feel they are delivering meat in a luxury vehicle. The exterior paint colors are different as the Renegade can come in a black, white, and tan combination.

It is an improvement over the purple and gray of the DX 3

Dynamax DX3 vs Jayco Seneca


No matter how you dress it up, the cab and back end of these RVs still look like trucks hauling different products. The color scheme on the Seneca is more exciting than the one on the DX 3 but no matter what you do to it, it still looks like a commercial delivery vehicle.

The DX3 has a more powerful engine than the Seneca but the latter has a bigger propane tank. That makes the difference when you are camping. While the chassis maker is the same, the Seneca builders went with the Freightliner® S2RV chassis and not the M2.

Another advantage the Seneca has is inside. It looks and feels more spacious than the DX 3. That could be due to the paint colors or it could be that Jayco is better at designing interiors than Dynamax.

The Seneca loses out on the engine as it only has a 360 HP Cummins ISB 6.7L and 800 lb-ft of torque. However, the Seneca is over $100,000 cheaper than the DX 3.

Dynamax DX3 vs Dynaquest XL

We do not see much difference between these two RV Class C models. All the features seem to be the same as well. The GVWR, GCWR, the height, length, and width are all the same with each other as is the wheelbase at 268 inches.

But that is not all that is the same with these two models. The fuel tank is the same size as are all the holding tanks. One major difference we found was that the DX 3 had a propane tank and the Dynaquest did not.

Another major difference is that the engine in the Dynaquest is more powerful than the DX 3. Its engine is a Cummins® 8.9L ISL Turbo Diesel Engine with 450hp / 1,250 lb-ft. of Torque.

Everything else seems to be the same. So if you want or need more power, then go with the Dynaquest but you will be paying anywhere from $60,000 to $80,000 more for the Dynaquest.

Some Final Words

Except for the usual inferior workmanship when built, the DX 3 seems to be a very good RV. That is if you like being seen in a commercial delivery truck turned into an RV.

The engine and other specs are fine but the paint job is not the best it could be. You get a lot for your money so hopefully, you will be happy with your purchase when you buy one.

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