Improve Gas MPG...?

[Jrama]

I think its only an advantage to turn your vehicle off if its going to be sitting idle for something like 40 seconds

[Immortal]

A stroker kit will put some of these under your hood.
Replacement parts seem to come free with alternators as well.


For better milage lower the jeep,  put skinny tires on @ 80 PSI,   and get rid of the transfer case. And you might want to try to find a old VW beetle to cut the roof off of and put it on the jeep for better aerodynamics

And he we go.... damn the badger resurrection. Thanks.

[Justink]

I get the best mileage when I don't drive it 
Have you done the basics as stated?
-lose some weight (in the vehicle  )
-free flowing exhaust
-Better air intake system
-And new plugs wire etc.
You should notice a difference, but maybe I don't know what I'm talking about.

[jpthing]

Wow...another "great" discussion.

Parabs, despite your diss, I feel your pain...it's really tough to have a discussion of an idea on this board without it getting kinda weird...I've just chosen to take it as part of the package deal because I have also met some really nice people on here and it's a great resource for local Jeep stuff. Just accept that this board has a different etiquette than most...

And as for me saying that my ideas definitely work, they do...rather than argue about it just pm me if you don't believe me and come look at my Jeeps...living, breathing, driving proof for those that are interested.

And on the topic of Zinc in oil...I find it very telling that many are still trying to make fun of me on this, but no one will contradict Corey Kruchowski (sp??) who posted up in my zinc thread that it IS a real issue. If you think it's BS go argue with him (no one has yet...)...or is it more of a popularity contest than a discussion?...I'm just sayin'.

As for the topic at hand a couple of random gas milage ideas that struck me while reading this are to lower the nose slightly so that the hood and roof are angled downwards or to construct a removable air dam for the front that could install into the front hitch rcvr or  maybe an angled deflector on the hood in front of the windshield...removing the front DS for a long trip could theoretically save some gas although I"d be more inclined to do it to save wear and tear on the double cardan and ujoints.


I believe it was bnine who said the K&N filters are junk, I couldn't agree more, these things let dirt into your engine it's that simple If you have one get rid of it and no I don't want to argue about it.

For those that really want to save gas check out "hypermiling" although I think these fools are probably just doing damage to their engines with low oil pressure and lugging.

The best way to save on gas (if you are able) is to adjust your travel times to when there is less traffic...you get zero mpg when you are stopped and terrible mpg when you are stopping and starting.

[BlackYJ]

As for the topic at hand a couple of random gas milage ideas that struck me while reading this are to lower the nose slightly so that the hood and roof are angled downwards or to construct a removable air dam for the front that could install into the front hitch rcvr or  maybe an angled deflector on the hood in front of the windshield...removing the front DS for a long trip could theoretically save some gas although I"d be more inclined to do it to save wear and tear on the double cardan and ujoints.

The problem is not just the front end, which your ideas are trying to resolve, but also the back end because of how square it is.  The boundary layer as it leaves turns turbulent which will cause a vacuum muck like a semi trailer causes but smaller.  Think rain drop

[jpthing]

True, but the front makes more of a difference than the back...the flat front creates pure simple drag, whereas the rear creates drag through turbulence, eddies, pressure differential, etc....

but ya, I`m down, ok, side skirts (detachable) , and a rear  `teardrop tail`....unfortuneately will add a lot more weight than a front skirt or deflector.

Having spent many years building and flying rc planes, I`ve learned that the little things make a bigger difference than you would expect (for wind resistance, not fuel economy) such as (in an airplane) things like wheel pants, taped seams, fairings attached to everything, etc...so consider removing the passsenger mirror, those rubber blocks on the hood, duct tape over the door handles etc  ...(joking).

On a more serious note, I would have to guess that the added smoothness and rigidity of the hard top would cause better fuel economy despite it`s greater weight...any thoughts?

[dac]

I've heard roof racks are not a good idea if you're trying to save money on fuel.

[parabs]

I've heard roof racks are not a good idea if you're trying to save money on fuel.

I can pretty much confirm this in my experiences.

[JackstandJohnny]

i've heard from a friend with a civic that putting a big fin towards the rear increases gas mileage.  something about the downforce decreasing the vortex behind the jeep due to the decreased angle of airflow coming off the roof of the jeep. 
not sure how accurate this is.   i can imagine its BS with a soft top because there's nothng really to mount the fin too

[esi]

i've heard from a friend with a civic that putting a big fin towards the rear increases gas mileage.  something about the downforce decreasing the vortex behind the jeep due to the decreased angle of airflow coming off the roof of the jeep. 
not sure how accurate this is.   i can imagine its BS with a soft top because there's nothng really to mount the fin too

The fin would have to deflect air down to have a positive effect. If a Corvette doesn't need one neither does a Civic
I think the shape of the front of a vehicle doesn't matter too much. Its the way the air flows off the back.
Here's the proof, and its back by education.
A float plane will barely get out of the water and won't climb out of ground effect if it has a small boat strapped to it if the boat is facing forward. With the boat turned around (flat end forward) the plane will easily fly. the flat end of the boat creates a dead air pocket in front of it. Air flows smoothly over the front and comes off the pointed end of the boat smoothly creating less drag than if the boat was reversed.

Not real useful information, but something to ponder

[Bnine]

And on the topic of Zinc in oil...I find it very telling that many are still trying to make fun of me on this, but no one will contradict Corey Kruchowski (sp??) who posted up in my zinc thread that it IS a real issue. If you think it's BS go argue with him (no one has yet...)...or is it more of a popularity contest than a discussion?...I'm just sayin'.

Im not sure what the issue is either. The only mistake you made with the zinc discussion was recommending the rotella oils because the zddp has been significantly reduced over the years.

ZDDP is an issue with flat tappet engines. Of all the topics you've brought up here, there is no question that one is valid.



Everyone gets the same treatment from me. If you put something out there that is wrong, dangerous, or just plain stupid, I will let you know. If you get stubborn, and refuse to listen to common sense, and experience, I'll let you know harder.

It doesnt matter if you are brand new, or the president of the jeep club. Anyone can look over my post throughout the years, and see that no one ever gets special treatment because of popularity.

If you are wrong, I'll explain to you why.

If you are being stupid or stubborn, I'll let you know.

If you are right, I'll back you up.


Its very simple, and its definately not personal.

[dac]

http://www.allpar.com/model/cj/details.html

An aerodynamic Wrangler may be an oxymoron, but aerodynamics did play a significant part in the design of the 1997 Wrangler. Wind noise, buffeting and soft top flap were at the head of the list of aerodynamic concerns with drag a secondary consideration. The primary objectives were achieved and drag was also reduced by 10-12%, improving highway fuel efficiency. The hard top drag coefficient is 0.55 and that of the soft top 0.58 (by comparison, a 1994 Ram was 0.42 and a 1995 Neon was 0.28). Because of a need to maintain the basic identity of the profile, changes are subtle. Changes include:
•a refined shape for the leading edge of the hood
•addition of a lip at the top of the windshield header
•addition of rounded soft top and hard top windshield headers
•rounded windshield pillars
•removal of the upstanding flanges on the windshield pillars and windshield header with the soft top
By reshaping the leading edge of the hood and adding a rounded windshield header to the soft top, top flapping is minimized. These changes guide air flow to keep it attached to the vehicle envelope and reduce the turbulence that causes flapping. These refinements also stabilize air flow at the cowl plenum, reducing pressure pulsation inside the vehicle and making HVAC system performance more stable. Rounded windshield pillars also reduce buffeting and wind noise around the soft top side curtains. The windshield header lip and rounded windshield pillars smooth air flow around the windshield to minimize buffeting of passengers with the top down.

Looks like the design engineers have already thought of the whole aerodynamics problem just like they've already figured out the fuel vs power vs cost issues.

You could change the look of your jeep with skirts and air deflectors but you'd give your jeep a serious identity crisis based on the above excerpt.  Sure the idea may be valid, but it's pretty dumb.  Who on this site is going to run any of these ideas while turning 33"+ mud tires on a vehicle they built to take offroad with a build goal of more ground clearance also knowing they may get body damage which could be more expensive and more likely with added paneling.  Depending on where you drive (city) the added weight may negate any fuel savings you think you're going to get.

[parabs]

Im not sure what the issue is either. The only mistake you made with the zinc discussion was recommending the rotella oils because the zddp has been significantly reduced over the years.

ZDDP is an issue with flat tappet engines. Of all the topics you've brought up here, there is no question that one is valid.



Everyone gets the same treatment from me. If you put something out there that is wrong, dangerous, or just plain stupid, I will let you know. If you get stubborn, and refuse to listen to common sense, and experience, I'll let you know harder.

It doesnt matter if you are brand new, or the president of the jeep club. Anyone can look over my post throughout the years, and see that no one ever gets special treatment because of popularity.

If you are wrong, I'll explain to you why.

If you are being stupid or stubborn, I'll let you know.

If you are right, I'll back you up.


Its very simple, and its definately not personal.

I think you should look up what an explanation is.  Your definition seems to include opinion, specifically yours.  I asked you pointed questions in which you responded like a child. 

Thanks for nothing.

[Zombie]

I have seen some vehicles with the little air "wings" on the back that push air down the back of the vehicle(usually on old suburbans and pos wagons) but they could help a little.

I think they were mainly to keep the back a little cleaner, but it could happen.

considering the weather we are having, try to get lots of big golf ball sized hail and that would increase the turbulance along the metal parts of the jeep allowing the air to more easily pass over the jeep, much like a golf ball.

but seriously, I think the best you can do, is have the vehicle maintained well, and run the tires at the "ideal" pressure for you vehicle(high enough to reduce some resistance, but not too high to wear the centers out of the tires or ride like a rock).

and remove the 30 pounds of dirt that have accumulated from all the fun over the years.

drive like an old lady could help.

with the larger tires on the jeep I get decent highway fuel economy as they are larger and I cruise at lower rpms, so skinny taller(within reason) tires would work(not practical for most, and looks odd), but it can help

I am just too lazy to take the roof rack off yet

cheers
steve

[Bnine]

I think you should look up what an explanation is.  Your definition seems to include opinion, specifically yours.  I asked you pointed questions in which you responded like a child. 

Thanks for nothing.

I explained to you over and over why your modern tech, unrelated exapmles were not valid in this discussion.

Everything from engine design, to aerodymanics and drivetrain loses. The fact that you are to stuck in your own head to understand common sense is not my problem.

I even gave you an example of a a member of this club that run a supercharger and what his results were. I also gave you a club members name of a guy who worked on said supercharger.

So dont get pissy with me because I debunked your bullshit speculation and unrelated tech with actual experience and facts.

Get over it.