Molded Fiberglass Trailers
Long time reader and first time poster. I have done a lot of reading about trailers and from time to time I read that molded fiberglass trailers are better. Yet in the marketplace there are few man...
Forum Discussion
rexlion,
The same approximate difference will be seen with a 6L gas or 6.X diesel as without the air drag/suction caused by the trailer the engine will get much closer to non-towing mpg's. Rolling resistance is linear regardless of speed driven and only 20% to 35% of the engine power is used for it. However, air resistance multiplies as speed increases and towing at approx 60 mph with a flat front takes about 3+ times the engine power to rolling resistance as does an aerodynamically rounded trailer front and rear of the same size and weight at 1.4 to 1.7 times the rolling resisitance. To acheive higher mpg's in cars you notice how the fronts, rears, and roof lines are now rounded with no sharp corners and the fronts are sloped for aerodynamics also above and below the hoods more like an airliner or a bullet is. More of the aerodynamics on vehicles and trailers is coming too so watch for it!
Also notice the shape of a ships hull as water acts about the same as the air only many times denser. Try pushing a flat ended barrel thru the water at even 30 mph and see the immense power it would take while our huge navel ships do it day in and day out with as little power as needed due to their hull shape.
A smooth sealed under body on a trailer helps also as there are no air dams/verticle surfaces for the passing air to push against creating drag. Every frame crossmember or tank under the trailer floor is an airflow catching bulkhead if not underbody covered. Not only much less air resistance but less propane or electric power will be needed to heat or cool a trailer with an insulated and covered underbody and it goes on year after year on every use. A very cheap item on or optioned money and energy saver on any trailer!
The 20% you experienced with your 2 different trailers with the same tow vehicle is very normal even though you push your 3.5L V6 engine harder. You are one of the smart people who have actually experienced it and knows the real difference. The difference seen in fuel economy can be as low as 15% or as high as 40% with the same vehicle driven the same on the same roads depending on speed and terrain. It's all documented in engineering manuals and books.
The same approximate difference will be seen with a 6L gas or 6.X diesel as without the air drag/suction caused by the trailer the engine will get much closer to non-towing mpg's. Rolling resistance is linear regardless of speed driven and only 20% to 35% of the engine power is used for it. However, air resistance multiplies as speed increases and towing at approx 60 mph with a flat front takes about 3+ times the engine power to rolling resistance as does an aerodynamically rounded trailer front and rear of the same size and weight at 1.4 to 1.7 times the rolling resisitance. To acheive higher mpg's in cars you notice how the fronts, rears, and roof lines are now rounded with no sharp corners and the fronts are sloped for aerodynamics also above and below the hoods more like an airliner or a bullet is. More of the aerodynamics on vehicles and trailers is coming too so watch for it!
Also notice the shape of a ships hull as water acts about the same as the air only many times denser. Try pushing a flat ended barrel thru the water at even 30 mph and see the immense power it would take while our huge navel ships do it day in and day out with as little power as needed due to their hull shape.
A smooth sealed under body on a trailer helps also as there are no air dams/verticle surfaces for the passing air to push against creating drag. Every frame crossmember or tank under the trailer floor is an airflow catching bulkhead if not underbody covered. Not only much less air resistance but less propane or electric power will be needed to heat or cool a trailer with an insulated and covered underbody and it goes on year after year on every use. A very cheap item on or optioned money and energy saver on any trailer!
The 20% you experienced with your 2 different trailers with the same tow vehicle is very normal even though you push your 3.5L V6 engine harder. You are one of the smart people who have actually experienced it and knows the real difference. The difference seen in fuel economy can be as low as 15% or as high as 40% with the same vehicle driven the same on the same roads depending on speed and terrain. It's all documented in engineering manuals and books.
