LightShip 4 Now Starting Customer Evaluation

[Rory (Lightship Team)]

Add to the discussion with the alternate (but approximate) formula:

FD = 1/4 AV^2

hey @redbaron , no simplifying our CdA! It took us years to make it worth breaking out )

 

[Rory (Lightship Team)]

The LightShip attracts attention. As people walk up to it I am using a new approach to initiate a discussion about this new RV.

I had a window cling banner made up at Signs.com and stuck it on the entry door of LightShip 4. When the question arises by a newby showing interest in the LightShip I ask them to consider the equation. The Q & A flows so easily from the equation.

Interesting how the window cling reflects around the LightShip windows.

View attachment 31290

View attachment 31291

@turbopilot , do you experience a noticeable performance difference in your plane between dry cold conditions and humid hot conditions? Theoretically there could be a small percentage point reduction in air density (“p”) from cold desert to hot coastal but curious if it translates into noticeable efficiency gains…

 

[redbaron]

hey @redbaron , no simplifying our CdA! It took us years to make it worth breaking out )

Of course your formula is the most accurate.

For my current inventory of Diesel pushers, 1 ton dually and various large trailers, approximate satisfies curiosity.


In all seriousness though, I like the approach @turbopilot is taking because that will definitely be a conversation starter.

 

[Rory (Lightship Team)]

Of course your formula is the most accurate.

For my current inventory of Diesel pushers, 1 ton dually and various large trailers, approximate satisfies curiosity.


In all seriousness though, I like the approach @turbopilot is taking because that will definitely be a conversation starter.

Haha yes!

 

[turbopilot]

@turbopilot , do you experience a noticeable performance difference in your plane between dry cold conditions and humid hot conditions? Theoretically there could be a small percentage point reduction in air density (“p”) from cold desert to hot coastal but curious if it translates into noticeable efficiency gains…

Humidity has a small impact on air density. Altitude and heat are the major variables. Every aircraft has a section in the manual about adjusting performance for density altitude. Density altitude not only impacts aerodynamics but also has a big impact on efficiency and power of most internal combustion engines. Pure EVs and turbocharged ICE engines are not significantly impacted by density altitude.

 

[turbopilot]

Haha yes!

It definitely works for the "liberal arts" majors. They have no idea what it means.

 

[turbopilot]

Continuing to baseline LightShip 4. I am ramping up road testing in the lower deserts of the SouthWest. For next week we are going to have temperatures in the 90's, so Summer time conditions for the testing over this period.

I took LightShip 4 to the CAT scales for the first weigh in. I will do a more detailed weigh in later looking at before and after weight distribution weights but for now I wanted a base line before loading in all the cargo associated with typical camping use.

So here are the conditions for this weigh in.

1. No cabin load, just as It was from the factory.
2. 480 lbs of water, 400 in the water tank and 80 in the hot water tank.
3. Factory Curt load distribution hitch set up with 5 chain links used.
4. Hitch weight before hook up was 680 lbs.
5. For PowerBoost Platinum empty weight 6,063 lbs, giving max load of 1,237 lbs.
6. Estimated Powerboost bed and cabin load for CAT weigh in 350 lbs.

So backing into the empty weight of the LightShip you start with the CAT scale weight on the four LightShip tires of 7,440 lbs. Next subtract 480 lbs of water to equal 6,960 lbs. Next add back 680 lbs of hitch weight and the empty weight is around 7,650 lbs.

But there is one more adjustment. I know from experience that weight distribution hitches will move about 200 lbs from the truck back to the trailer wheels, that would come to 7,450 lbs empty weight of the LightShip. And finally there is the 100 weight distribution hitch whose weight is shared by both the LightShip and the PowerBoost.

Bottom line, I know for sure before adding cargo the LightShip and PowerBoost combine gross weight is 14,420 lbs rolling down the road. I think the stand alone LightShip empty weight for this Cosmos model is probably pretty close to the specification of 7,300 lbs, maybe a bit more.

 

[turbopilot]

My F-150 PowerBoost is equipped with a rear web camera. It updates every 60 seconds anytime the Powerboost is in motion.

Here is a link to live web page when the PowerBoost is in motion.

F-150 Rear Reolink Camera

 

[Porterhouse]

You really need a 3/4 ton truck for this trailer. An F-150 won't be totally safe. I understand the attraction of the powerboost 7.2 KW generator feature, though. The good news is that it should be available in an F-250 sometime in 2026.

 

[Holdmybeer]

You really need a 3/4 ton truck for this trailer. An F-150 won't be totally safe. I understand the attraction of the powerboost 7.2 KW generator feature, though. The good news is that it should be available in an F-250 sometime in 2026.

“Girl, you in trouble”

 

[redbaron]

“Girl, you in trouble”

Gotta agree….talk about not knowing your audience or subject.

 

[turbopilot]

Gotta agree….talk about not knowing your audience or subject.

And for those who like facts to contrast with unfounded opinions, here are the towing specifications for the F-150 PowerBoost with the Tow/Haul Option 53T. And these specifications to do not account for towing an RV trailer with a 50% to 100% reduction in hitch force associated with much reduced aerodynamic load or the use of a power system in the towable RV. Bottom line the F-150 PowerBoost with the HD tow package is around 4,000 lbs under the GCWR for this truck when towing a LightShip and 3,000 lbs under the Maximum Loaded Trailer Weight for the same model.

And diving very deep into the fine print the F-150 PowerBoost and LightShip easily pass the frontal area limitations associated the Ford trailer towing limits.

The maximum frontal area limitation for a Ford F-150 when towing refers to the recommended limit on the combined frontal (projected) area of the truck and trailer exposed to wind resistance. Exceeding these guidelines can significantly reduce towing performance, such as causing excessive drag, reduced stability, higher fuel consumption, overheating, or straining the engine/transmission—especially at highway speeds or in adverse conditions.

According to official Ford towing guides (including the most recent for 2025 and 2026 models), the limits for a standard F-150 pickup (non-Lightning) are tiered based on the vehicle's configured maximum trailer tow rating:

• 55 square feet for vehicles with a trailer tow rating of 7,700 lbs or less.
• 65 square feet for vehicles with a trailer tow rating of 7,701 lbs or greater.
• 75 square feet for all 5th-wheel and gooseneck applications (these are often exempt from lower bumper-pull limits due to better aerodynamics and weight distribution).

These values represent the maximum trailer frontal area to consider in the combination (truck + trailer). Ford notes that exceeding them "may significantly reduce the performance of your towing vehicle."

Older model years (e.g., pre-2024/2025 in some forums and guides) sometimes referenced a flat 60 sq ft limit for non-5th-wheel/gooseneck setups with higher tow packages, but current official documentation uses the tiered approach above.

Notes:

• The F-150 Lightning (electric variant) has separate, generally lower limits (e.g., 40–60 sq ft depending on battery and tow package).
• These are Ford's engineering recommendations for safe, optimal performance—not strict legal limits—but ignoring them can void aspects of warranty coverage or lead to real-world issues.
• Always check your specific model's towing guide (available on ford.com or via your VIN at a dealer) or owner's manual for exact details, as limits can vary slightly by year, engine, axle ratio, tow package (e.g., Max Trailer Tow), drivetrain (4x2 vs. 4x4), and other options.
• Trailer frontal area is typically calculated as width × height (including any protrusions like awnings or AC units), not including the tongue/hitch area.

 

[Holdmybeer]

Just for clarities sake. The two forces exerted on the hitch are downward ( tongue wt.) and horizontal (tractive or drawbar pull and surge when braking) You might reduce some or all of the tractive force at the hitch with a drive system on the towed vehicle but the second the drive system is turned off the holy trinity of drag comes back into play. Inertia, rolling resistance and aerodynamic drag. There’s not going to be any 100% reduction in tractive force ( drawbar pull) due to aerodynamics and aerodynamics have zero to do with downward force ( hitch weight) .

 

[turbopilot]

There’s not going to be any 100% reduction in tractive force ( drawbar pull) due to aerodynamics and aerodynamics have zero to do with downward force ( hitch weight) .

That is all correct but the forces associated with rolling resistance are constant (except for hills) and are typically overwhelmed by aerodynamic forces above 40 MPH. The LightShip appears to have a light hitch, probably not exceeding 10% of the GW of the fully loaded RV, so all the forces at play favor an F-150 with the HD towing package that is well within the specifications of the manufacturer.

 

[Holdmybeer]

Whether or not your truck can tow that trailer aside, Inertia ( weight of your trailer) , not rolling resistance, would be relative to hills and neither have anything to do with aerodynamic drag.