Lmao im at 26 l per 100 pulling my rig as per previous post i would say your tabs need some attitude adjustments lolHi. The perfect shape is a teardrop, big in the front and a tail in back to reduce back pressure or vacuum. The airstream trailer comes close. I have installed air tabs on the back edge of my apex 194 which claim to be vortex breakers, similar to dimples in golf ball. They claim 5%. I Saw maybe a reduction from 22 lp100 km to 21.5, which is maybe 2%. As said in the postings, the square rears cause the majority of drag. Many of commercial wings have builtin flow disrupters builtin.
1.5 l p 100 km improvement is actually fantastic.
I am looking for improvements to extend my range. I have a 26 gallon tank- 20 usuable gallons. I have taken off my KO2 LT tires and switched to Michelin LTX series tires.
Retired Mech. Engineer
2015 Tundra, Forest River Apex 194
22 litres per 100km or aprox. 10.7 mpg at 60 mpg.
Last May we pulled through from Calgary to London we were warned about the lack of stations and them being closed because of Covid we took 2 large jerry cans to be safe. Ended up using them east of Medicine Hat bucking a fierce head wind lolAir Tabs are a brand name that stick on the side of the trailer. Gas mileage is nice, but want range, 4 hrs driving. At 60 mph..In northern Ontario I paid $1.50 per litre and gas stations can be more than 3 hrs apart.
No offense my dad is an engineer charted recorded graphed everything and i mean everything - he still has mileage logs from our trip to San Diego in 1976 ( i love rummaging through them all and i have inherited the same phyco tendencies lol i love to compare) but until you are comparing environmental conditions which is why a wind tunnel comes into play your findings are inherently inaccurate. Please dont take me wrong i love the idea - but in order to work properly your defector needs to be much closer to the trailer ie mounted to the trailer to work but then you have the 3ft void between your audi and the trailer which causes drag.Steve I understand what you say but this trip from Edmonton to Rockies I do at least 4-5 times each summer and the numbers have always been in the same range. The drop with the deflector was way more than a noise. Looking at it from an engineering viewpoint, the weight of my trialed is 2/3 of my tow vehicle yet when hooked up the gas consumption was more than 3 times normal. Most of it I suspect is due to the drag, I.e. head pressure of air (extremely bad shape of the trailer). So even a slight measure to reduce the drag should have noticeable improvement in gas consumption.