Flow Below Added

I have taken them off trucks before because I didn't like the looks, and more importantly they put a hindrance on a proper pretrip.

At least you installed them in case a DOT officer asks you to remove them to look at the lugnuts. It would be embarrassing to say you did a thorough pretrip and weren't familiar on removal like most company drivers.

 

I'm familiar. Push and twist. I've just never seen anyone remove them to pretrip.

 

I used to think this way but really when you think about it, why would a mega be at anymore advantage then a single operator? If the ROI is there for 1000 trucks then wouldn’t it be the same for one truck? Yes, they may get discounts but they also get discounts on fuel. I don’t run this particular aero model but applaud siiman for investing in efficiency. If you can’t afford to invest, then your in trouble IMO.

Yea, they have more revenue but they also have more expenses.

 

These aren't for me, but I'll look forward to seeing how they work out for you. IMO aero device gains/ROI are advertised under ideal conditions: flat terrain, perfect pavement, and zero wind. Reality is that's maybe 5-15% of my miles. Any of those things gets a bit adverse, and suddenly that 0.1 mpg vanishes. Then there's maintenance and replacement. I'll let someone else be the pioneer with those.

Case in point: trailer tails. I got them on my trailers when new. They do work. Up to 0.4 mpg in ideal conditions. Reality is barely measurable. Crunch one and the savings is lost for years. They also leave the doors sticking out a couple inches more when hooked open, which is a door strike waiting to happen at some places. My new trailer order does not have them. The fuel savings does not pan out long term in my operation.

Best "investments" to save fuel so far? Electric HVAC in the bunk with no running engines to tend, and perfect preload on wheel bearings using the Dr Preload tool and nuts. The latter on just my usual trailer has offered a 0.2 mpg improvement consistently, regardless of terrain and wind. Not to mention substantially improved tire wear. That's real money I can see without too much mathematics gymnastics.

 

What speed can you get with an RPM of 1100 in the highest gear?
I noticed extremely high fuel mileage at low RPM with Volvos.
If you can deliver on time with 60-62 miles/h maximum speed you'll notice better savings.
Of course the best savings are when you park the truck.
And maybe that's the best response to low paying loads.