Frontal Area

[JVFLDF]

I am brand new to RVing, and want to be safe and comfortable.I have a 2018 Nissan Frontier Crew Cab 2wD. Max towing Capacity is 6300lbs Tongue Load 630lbs. Max GCWR 11,250lbs. I found expandables well under these ratings, I figure 1000 lbs under to be safe. The maximum trailer frontal area is 30square feet. Yipes.. Is there a formula to compensate for this frontal area? I couldn't even find a pop-up with a frontal area that small. I had the Frontier set up with a tow package when I purchased it and it has a class 4 hitch. I have read so much about frontal areas that all it has done is lead me to more confusion. Any help (clarification) would be greatly appreciated.

[gmw_photos]

Ford states in their literature:

Frontal area is the total area in
square feet that a
moving vehicle and
trailer exposes to air
resistance. The chart
shows the maximum
trailer frontal area that
must be considered
for a vehicle/trailer
combination. Exceeding
these limitations may
significantly reduce the
performance of your
towing vehicle.

[blt2ski]

Bobbo wrote:

sgip2000 wrote:
For frontal area, subtract the area blocked by the truck.

Look at the front of the truck when hitched up. The areas of the front of the trailer you can see are the areas that are added up for frontal area.

Put a cap on your truck and the frontal area will decrease.

I would like to see the studies to back up the assertion that you subtract the area blocked by the truck. Please post your sources.

I would like to see this source too! Frontal area has always in my studies, specing of larger commercial trucks etc been the total of the tallest, widest points looking from the front back.

Marty

[Bobbo]

sgip2000 wrote:
For frontal area, subtract the area blocked by the truck.

Look at the front of the truck when hitched up. The areas of the front of the trailer you can see are the areas that are added up for frontal area.

Put a cap on your truck and the frontal area will decrease.

I would like to see the studies to back up the assertion that you subtract the area blocked by the truck. Please post your sources.

[BarabooBob]

Before I bought my truck and TT I did a lot of research into using a topper to help with drag from the trailer. Most of the articles claimed that a topper did nothing to help with trailer drag because the space between the topper and trailer was big enough to eliminate any benefit. they even tested canoes and kayaks to see if there was a benefit. Nothing seemed to matter much.

[sgip2000]

For frontal area, subtract the area blocked by the truck.

Look at the front of the truck when hitched up. The areas of the front of the trailer you can see are the areas that are added up for frontal area.

Put a cap on your truck and the frontal area will decrease.

[BurbMan]

Lynnmor wrote:
Once up to speed, weight isn't a big factor except on hills. The fact that you will be towing a "parachute" will keep you deep into the throttle almost all of the time. Your vehicles cooling system and other mechanical systems may not be up to that work load. You can compensate somewhat by driving much slower, which will save fuel, but it sounds like you have a very small dog with a very large tail.

This is right on the money. Just about all smaller SUVs and mid-sized trucks have these frontal area limits in addition to weight ratings.

Essentially most pop-ups are 8' wide with a box depth of 3.5' or so, giving you 28' of frontal area. I would say you would be fine with any pop-up, leaving a bunch of carrying capacity on the truck to load up the bed with stuff.

You might also look at an ultra-light hybrid....even though are likely over the 30 SF limit, they tend to have more rake in the front to decrease wind drag.

[aftermath]

This is interesting. I have never heard of a total frontage requirement for towing but it really makes sense. Frontal area has lots of variables as earlier noted. I have noticed that some trailers have a more prominent slope to their fronts than others and then there are the V shaped ones.

I can tell you from first hand experience that wind resistance does make a huge difference. I towed a 21ft Hybrid with my Tundra and was getting just about 12mpg. We moved to a 25 ft Airsteam that was actually 5 feet longer and weighed 2000 pounds more. Using the same truck I am still getting 12 mpg on average. Only difference was weight and design of the front of the trailer.

[blt2ski]

If one wants to go back to a poster put out by Ford I saw in the early 90s....
Max F series trailer at the time was 10,000 lbs up to 80 sqft. 7500 81-100 ft 101-120 was 5000 lbs. It was not recommended you two over 120 square ft.
The ranger Aerostar had a 5000 or 6000? Lb rating. With a max of 60square ft. 61-70 reduce by 1000 lbs.71-80 reduce by total 2000 lbs. Over 80 square ft was not recommended by Ford.
A number of ways to look at this per say.
Marty

[gmw_photos]

I have a 2006 Frontier that I use to tow with. The 2006 is identical mechanically to the newest Frontier. My 2006 had a stated frontal area limit of 60 sq ft. The newest, as the OP states is 30 sq ft. Why the change, Nissan ?

I suspect it has to do with meeting J2807, which came out after my truck was built.

I don't worry about it. I pull either my 7' wide 10' tall Funfinder, or my similar size horse trailer with the truck. I have 155K miles on it, about 60K of that towing. The scangage on the dash shows real-time water temp, and it only runs 3 to 5 degrees hotter when towing vs empty. Good to go with either trailer.

I don't know the exact answer on how they determine frontal area. As others have stated, there are several factors such as the slope or other shape of the front of trailer. On my camper, there is no part of the front that is straight up and down flat. On my horse trailer, there is. I don't over think it. It either works or it doesn't. In my cases, it works. Good enough for me.

BTW as a matter of reference, our 2006 F350 diesel dually has a frontal "limit" of 60 sq ft.

[blt2ski]

I've always seen frontal area as the WHOLE area going forward. If pulling a trailer 8 'w, by 10' tall, you have 80 square ft. Even if the tow rig takes up a 7x7 or 49 square ft.
Then one need to factor in aerodynamics of the rig. How smooth, rough, flat fronted etc the rig is as to.How much HP one mat need to move a given rig down the road. This factor can vary HP needs by plus minus 30% from ave.
For most of us with RVs, we are better off mpg, lesser HP needs with a slightly heavier fiberglass walled trailer vs a lighter aluminum corrugated side trailer. The extra Wight does not strain your rig as much as additional wind resistance as aluminum siding adds.

Marty

[dodge_guy]

I`ve never seen it posted anywhere or explained. But I believe "frontal area" is defined as the area that is above the roofline and possibly what is wider than the vehicle.

[MitchF150]

So, with that frontal area "limit" you have, you can tow a flat bed car hauler or a boat to that 'tow rating' limit... I think what the manufacture is trying to say is that towing a full size travel trailer that has a HUGE frontal area with that rig is not really not recommended..

What kind of travel trailer can you haul with that rig? Dunno.. Really depends on what your towing performance expectations are.

Good luck!

Mitch

[blt2ski]

30# is a really small trailer, IE a tent trailer! Or is that additional sq ft vs base truck frontal area? But with this said, yes frontal area adds to HP needed to pull at a given speed. Some figures I did a number of years ago to compare some trailers I pull and GCW I was running down the road

15k lbs, 70# is 105HP at 60
15K 90# 135HP
18K at 70# 115hp
25K at 70# is 135hp

Gives you some rough numbers idea as to what is more important from a how much HP you need at a given wt and frontal area.

Another to add into the equation, at 15K lbs, 40HP per 1% grade additional from level ground.

Marty

[Lynnmor]

JVFLDF wrote:
Thank you all for the replies. I plan to stay well under the Max Towing capacity, I have found a couple of hybrids that meet that criteria. My concern is the Frontal Area. "Maximum trailer frontal area 30sq feet" The expandables I am interested in fall 1000lbs below the max towing capacity the frontal area calculates out to be 84sq ft. What would be the effects of towing this with my Nissan Frontier? Does the decrease weight compensate for the increased area? How would this effect safety? Or, would it just effect how I should drive i.e. slower, mpg. etc.?

Once up to speed, weight isn't a big factor except on hills. The fact that you will be towing a "parachute" will keep you deep into the throttle almost all of the time. Your vehicles cooling system and other mechanical systems may not be up to that work load. You can compensate somewhat by driving much slower, which will save fuel, but it sounds like you have a very small dog with a very large tail.

[Y-Guy]

Moved from Dingy Towing to the Towing forum.