nissan kingcab aerocap

[BMACM65]

Looks like mine. I did one for my '98 Dakota. Went from 18 to 22mpg but the computer soon learned and screwed me! I took it off. Next time, a slight redesign and build from better materials.

[Daox]

Originally Posted by BMACM65

Looks like mine. I did one for my '98 Dakota. Went from 18 to 22mpg but the computer soon learned and screwed me! I took it off. Next time, a slight redesign and build from better materials.

First off welcome to the site.

Second off, your computer will learn of your aerocap the instant you start moving. It knows this because your vehicle moves easier through the air. If your mileage dropped after the fact I can assure you that it was not the computer making changes, it was other variables.

[JV-Tuga]

Originally Posted by sepp

like nightrider when i use a gps

You mean you have one of these?...
Knight Rider GPS by Mio - Let K.I.T.T. give you directions!

[BMACM65]

Originally Posted by Daox

First off welcome to the site.

Second off, your computer will learn of your aerocap the instant you start moving. It knows this because your vehicle moves easier through the air. If your mileage dropped after the fact I can assure you that it was not the computer making changes, it was other variables.

Well, actually I have done many things to improive mpg's. Some worked, some didn't and after a few starts, none did! period.
It's OBDII
Dominant
Big
Oil

spelled backwards!

[sepp]

hello again, the first complete tank i did with the cap on felt rather disappointing. i calculated that my consumption was of 9.2 liters, wich is still an improvement compared to the 10 plus liters i averaged before. but obviously alot less than my early over-optimistic estimation that i was doing around 7 liters.
but! the trips i did with that tank were unusually mpg-unfriendly compared to what i do normally. verry few highway and lots of verry small trips. i even hauled a bathtub around in the back with the cap removed...
now im halfway through my second tank, and i have also decided to pump up the tires to right under the maximum of 40 psi. and there is a difference already on the gauge and on the feeling. and the fact that it's getting milder ouside is helping also.
ill report the consumption as soon as the tank is empty again.

ps, i have a question for those with a scangauge.

what is the most efficient way for me to go pick up my girlfriend?
the shortest way wich i always take is 1 km on road and 8 km on highway, and the other way without highway would be 11-12 km on road mostly limited to 50 kmh.
with keeping in mind that im driving a pick-up, i ususally cruise at 80-90 kmh on highway. and that my gears are rather short so im basically always in 5th from 40 to 130 km/h

basically is it best to cruise for 10 minutes with the engine mostly at a high rpm (2500), or to drive on smaller roads for 13-15 minutes with the engine mostly around 1300 rpm? knowing you oftenly need to slow down, turn stop etc...

since i have no scangauge i can't tell!
thank you

[GoodOak]

Sepp, I am very impressed. I recently bought a Nissan Frontier and after seeing your thread here, I am considering making my own cap. I don't have much free time to work on it, or experience, but my father has built several wood/fiberglass canoes...

Have you found any good options for the wheel covers? And what did you use to cover your grill. That looks very clean.

Keep up the good work!

[Big Dave]

Short-term MPG tests give too much scope for distorting factors (i.e. head and crosswinds, traffic, rain or snow).

A quick snap shot is of VERY limited value.

Do an A-B-A test with each leg about four tankfuls. A shorty test could be distorted by how you fill the tank.

I cannot believe an aerocap failed to improve mileage in a valid test.

[GoodOak]

Oh, one more question for you Sepp, do you notice your truck over-heating at all once you blocked up all of the grill? I am thinking of doing the same for my truck but it is a work truck that hauls trailers and loads of stone and mulch. I am worried about overheating problems, which is why I am thinking of making whatever I try out to cover the grill easy to add or remove in case the truck would be working hard on a hot day.

[sepp]

@ goodoak, the front grill cover was just a temporary cardboard peice cut out to fit in the opening and covered with black masking tape to make it watertight and discrete.
meanwhile my dad couldn't help ripping it off because some garagist said it was bad for the engine (i could have strangled him)
i never saw an increase in temperature, and not even the engine warming up faster (wich i hoped it actually would do, but it didn't) fact is that the engine still gets more than enough fresh air to keep cool, you don't need a direct frontal air supply. but i suggest you build something temporarely and see if your temp changes.
i have not found any acceptable method for getting wheel covers to hold on my rims yet unfortunately.

and im glad to hear you want to make a cap, im actually thinking of making a new one. i suspect that the cap i have now is too heavy and may actually increase my consumption at slow speeds below 50 km/h where its just more dead weight. and that the end-curb may be to steep downward so at speeds over 80-90 km/h the airflow detaches. im not 100% sure but i feel it happening once i go over 90 km/h.
the cap i made is just too solid, you can walk on it and i think it weighs around 60 kg (120 pounds?)

i would like to make a new one wich would be as light as possible with much thinner wooden beams, wich would not go down so low and would have plexi-glass windows. and also wich would allow the above part to be opened or even removed to haul large objects in the back.
i don't know yet with what material i will cover it, i saw that aluminium sheets are available in verry thin thicknesses and are cheaper than the thinnest metal sheets. im not planning on using fiberglass and polyester anymore, too expensive and hard to manipulate and can't be recycled. while a wood-aluminium combination is fully recyclable.

about the consumption with my current cap, the last 2200 km i averaged a verry nice 8.3 liters, wich is 2.4 liters under its EPA!

[elhigh]

Originally Posted by sepp

what is the most efficient way for me to go pick up my girlfriend?
the shortest way wich i always take is 1 km on road and 8 km on highway, and the other way without highway would be 11-12 km on road mostly limited to 50 kmh.
with keeping in mind that im driving a pick-up, i ususally cruise at 80-90 kmh on highway. and that my gears are rather short so im basically always in 5th from 40 to 130 km/h

Without more immediate information, it's difficult to tell what your best option is, but it may be a wash. The 50kmh route is probably going to deliver your best fuel mileage, but you might wind up using just as much fuel by covering a greater distance. Without instant feedback on your fuel economy performance though, it's really tough to say whether one is better than the other in terms of actual fuel use.

Love the cap. I need to make one like that.