2002 QX4 Roof Rack Cross Bars Removal

[brickbox]

Can someone please direct me on how to remove the cross rails/bars in the roof racks? I am driving 100+ miles each day without anything on the roof - so I am hoping that removing these would net an mpg or two.

I tried loosening the end caps, but all this allows me to do it so to adjust and move them back and forth. Am I supposed to remove the 4 tiny hex screws that are mounted on the inner side?

[EdBwoy]

See if this thread helps you, or the roof/body and trim section of the FSM. IIRC, I have to remove the hex-mounted caps the the front and back of the rails to slide both types of crossbar anchors off.

Btw, I foresee no MPG improvement due to this alone. Even the AWD vs RWD specs are limited by the engine vs the mass and profile it has to drive. Good luck

[brickbox]

Thanks! I did see his thread and wasn't sure if I had to go through all the pains in order to just remove the cross bars. I will try removing the hex mounted caps at the ends of the rails to see if the cross bars can just be slid out.

That's disappointing to hear that the cross bars removal wont help in any way. Granted the car has almost brick like aerodynamics and the profile improvement against wind resistance would be minimal with cross bar removal, I figured it was worth a shot if the assembly/disassembly is relatively easy.

I have read the older MPG improvement threads. Are you aware of any ideas outside of installing the manual locking hubs to help with MPGs? I have already tempered my driving habits and don't cross 73-75mph in 70mph zones to get about 230-250 miles before the low fuel light comes on.

[EdBwoy]

What is your calculated fuel economy - miles between fills vs. gallons to fill up?
Has it changed with the cold season or do you not get winter weather?

Honestly, there's not much you can do if you are at those high speeds. I bet the 4 speed is keeping your RPMs high, right?
2350 rpm on OD might give you the best yields, but then you're probably going to be driving at 60mph on flat terrain and hoping there are no unaddressed maintenance issues.

This simply isn't the vehicle to attempt hypermiling on.

[brickbox]

Lol I live in Pure Potholed Michigan. I have been varying between 15.8mpg and 17.17 mpg in the winter (depending on how cold it is and how lead footed I am). Prior to the white stuff hitting the ground, I was getting consistent 17.42 to 18.63 mpg (there were about 15 fill ups before snowing coming down).

Yeah, the 4 speed isn't really helping. It gets pretty close to 2800RPMs going about 75mph. And go any slower, people will run you over here on the freeways.

I guess you are right that the QX4 is probably not the best vehicle to hypermile, but I hate having to get rid of her. It runs great except for 2 oil leaks I gotta fix and the cruise control no functioning issue. Plus it just rolls through the bad weather...that ATTESA

[QX4ME]

I remember after I bought my 02 4WD, I drove once round trip 98% highway at abound 75 mph for maybe 200 miles, the mpg was about 18+. Now I drive it mostly local, about 15 or a bit less mpg. I too tried taking the cross bar off but it didn't help the mpg.

I got a crazy idea, inspired by my 06 Honda Odyssey EX-L. It has the VCM, variable cylinder management. When cruising, it deactivates three cylinders. If we can find a way to do the same, we can increase mpg. If I remember correctly, Odyssey with VCM is rated 20/28 mpg (city/highway), without VCM is 19/25 mpg.

[Mike W.]

All eyes here on the MPG part, but that's what I've been seeing too. They look like a royal pain to get to, but O2 sensors can make a difference on other cars, so I assume these also. They might pass smog, but my experience is the 100K changeout interval is a little optimistic for optimum mileage and performance. Again, with other vehicles. Mine mostly sees miles on vacation and I'm determined to get them done before vacation this summer. Not looking forward to it though. I got 18 on vacation last year, about as good as can be expected I suspect although I hope to see another 1 or 2 MPG with new O2 sensors.

Aerodynamics are another story, I'm seeing a cx of .58? That's coefficient of drag, not total drag and astoundingly bad. Not much I can do about it though.

[brickbox]

I remember after I bought my 02 4WD, I drove once round trip 98% highway at abound 75 mph for maybe 200 miles, the mpg was about 18+. Now I drive it mostly local, about 15 or a bit less mpg. I too tried taking the cross bar off but it didn't help the mpg.

I got a crazy idea, inspired by my 06 Honda Odyssey EX-L. It has the VCM, variable cylinder management. When cruising, it deactivates three cylinders. If we can find a way to do the same, we can increase mpg. If I remember correctly, Odyssey with VCM is rated 20/28 mpg (city/highway), without VCM is 19/25 mpg.

I looked into it. Looks like deactivation is almost impossible. And activating/re-starting the cylinders would requite a whole new level of controls that our vehicles can't handle

[nickelghandi]

Thanks for the link to my thread!

The crossbars are actually pretty easy to remove. I did that on my 1999.5 Pathfinder back in the day to try to save some MPG. I gained maybe 1 MPG out of it and then had to put them back when I wanted to throw a canoe on the roof.

For the immediate question:
I think you can just remove the two front end caps and then all of the roof rack hardware will slide out of the holding brackets. It is either a T25 or T30 star bolt.

As far as picking up some MPG the best thing I did was slow down. Cruising along at 60-65 mph I can get 20 MPG out of my 2004 Pathfinder with larger tires, grille guard, and a 2.5" lift. I do have a pretty free flowing exhaust, but I seriously doubt that is making any difference except maybe at WOT.

I took mine from 11 city and about 15 highway to 16 city and 20+ highway just by timing lights and stops. I used a scangauge and monitored my driving habits as I went. Passing, going up hills, changing lanes, etc. will suck down gas really fast. Hyper-miling might not make much difference in terms of actual mile per gallon gains, but that is a 25% increase for me. I haven't heard of many other vehicles that can claim a 25% increase to their fuel economy.

Some front or side skirts might help you a bit on that drag. It would increase the frontal exposure, but maybe smooth it out to help it glide a bit better through the air. The more it looks like a boat, the better MPG you will have.

Lighter wheels and tires will make a difference too. On the highway larger diameter tires may actually be helpful because you can be traveling the same speed at a lower RPM. If it is hilly then no, but flat roads it is possible.

You can unplug the injectors and just run 4 cylinders in v-configuration. You will throw a ton of codes and possibly fry your ECU or burn pistons/walls, but it might be interesting to see what kind of MPG gains you could get.

Eliminating as much weight as possible would make a difference as well. Strip out the rear seats, follow my roof rack removal guide and just take everything out of the vehicle. Pull out the heavy carpet and sound deadening insulation. Remove your running boards if you have them. Remove your spare tire and tire carrier hardware. Heck, delete your muffler and resonators and run a pipe straight back from the cat or bend it into a side exit exhaust. It will be lighter and also free up the exhaust some. Remove the towing kit if applicable. It depends on how far you are willing to go and how much noise and misery you will put up with to achieve your goal.

Manual locking hubs are supposed to make a difference if you have 4WD. Or if you never use the 4WD delete that entire system freeing up weight and eliminating the drag it has on your drive train.

Premium fuel make a difference in my 2004 Pathfinder. The VQ needs high compression to put out enough power to push the vehicle.

Like I said I can push 20+ MPG highway now and I have roof racks and other aerodynamic drags as well as a slight gear ratio deficit with the larger tires. I will drive 65 and people can get mad if they want. As long as you aren't holding the left lane or something they have no right to get mad. I live in KY and people are usually pretty nice on the roads here, but no matter where you live or how fast or slow you go, there will always be someone that wants to go faster or slower than you.

[brickbox]

Thanks for the link to my thread!

The crossbars are actually pretty easy to remove. I did that on my 1999.5 Pathfinder back in the day to try to save some MPG. I gained maybe 1 MPG out of it and then had to put them back when I wanted to throw a canoe on the roof.

For the immediate question:
I think you can just remove the two front end caps and then all of the roof rack hardware will slide out of the holding brackets. It is either a T25 or T30 star bolt.

As far as picking up some MPG the best thing I did was slow down. Cruising along at 60-65 mph I can get 20 MPG out of my 2004 Pathfinder with larger tires, grille guard, and a 2.5" lift. I do have a pretty free flowing exhaust, but I seriously doubt that is making any difference except maybe at WOT.

I took mine from 11 city and about 15 highway to 16 city and 20+ highway just by timing lights and stops. I used a scangauge and monitored my driving habits as I went. Passing, going up hills, changing lanes, etc. will suck down gas really fast. Hyper-miling might not make much difference in terms of actual mile per gallon gains, but that is a 25% increase for me. I haven't heard of many other vehicles that can claim a 25% increase to their fuel economy.

Some front or side skirts might help you a bit on that drag. It would increase the frontal exposure, but maybe smooth it out to help it glide a bit better through the air. The more it looks like a boat, the better MPG you will have.

Lighter wheels and tires will make a difference too. On the highway larger diameter tires may actually be helpful because you can be traveling the same speed at a lower RPM. If it is hilly then no, but flat roads it is possible.

You can unplug the injectors and just run 4 cylinders in v-configuration. You will throw a ton of codes and possibly fry your ECU or burn pistons/walls, but it might be interesting to see what kind of MPG gains you could get.

Eliminating as much weight as possible would make a difference as well. Strip out the rear seats, follow my roof rack removal guide and just take everything out of the vehicle. Pull out the heavy carpet and sound deadening insulation. Remove your running boards if you have them. Remove your spare tire and tire carrier hardware. Heck, delete your muffler and resonators and run a pipe straight back from the cat or bend it into a side exit exhaust. It will be lighter and also free up the exhaust some. Remove the towing kit if applicable. It depends on how far you are willing to go and how much noise and misery you will put up with to achieve your goal.

Manual locking hubs are supposed to make a difference if you have 4WD. Or if you never use the 4WD delete that entire system freeing up weight and eliminating the drag it has on your drive train.

Premium fuel make a difference in my 2004 Pathfinder. The VQ needs high compression to put out enough power to push the vehicle.

Like I said I can push 20+ MPG highway now and I have roof racks and other aerodynamic drags as well as a slight gear ratio deficit with the larger tires. I will drive 65 and people can get mad if they want. As long as you aren't holding the left lane or something they have no right to get mad. I live in KY and people are usually pretty nice on the roads here, but no matter where you live or how fast or slow you go, there will always be someone that wants to go faster or slower than you.

That's a ton of possibilities you put in there! Already got rid of the towing kit. I am in MI where I need the 4WD (getting 6" today - yay!) and everyone's being an a$$ on our potholed roads.
But for now, I would like to keep my car stock and not go down the path of stripping everything except the driver's seat

I know of someone who tried the "V4" configuration on their older 4 runner. If screwed up the piston/walls while gaining about 3-4mpg. But that thing could NOT get out of its own way running on 4 cylinders.
I didn't realize there would be that big of a difference between 87 and 93 octane fuels. I guess I could give it a shot. This week I have been trying to drive between 70 and 73mph steady and use the brakes as little as possible while accelerating very gently. Typically by 190 miles, I am just below a quarter tank. Today I am still above a quarter tank at 190 miles since last fill up!

I just want an 87 octane sipping proper 4WD SUV, giving me 30mpg and has all the niceties and is quiet [I am kidding obviously....but getting 20mpg on the freeway running 75mph would be fantastic from my wallet's standpoint]

[nickelghandi]

I just want an 87 octane sipping proper 4WD, giving me 30mpg and has all the niceties and is quiet [I am kidding obviously....but getting 20mpg on the freeway running 75mph would be fantastic from my wallet's standpoint]

Here it is!


That should do all you want. It has such a rugged, off-road look to it too.

But seriously, good fluids, removing the roof-racks and possibly some manual hubs should get you around 20 mpg if you keep it under 80 and time a few lights to avoid stops and starts. You could try playing with your final gear ratio, but that might do more harm than good. I have always thought these trucks needed just one more gear for cruising. Nearly 3K RPM at 80 MPH is not very efficient in these engines.

[brickbox]

Lol. I was looking at buying one of them once they are sufficiently depreciated in a couple of years. But they get barely middling reviews across the board. Plus, dont know if I can from an Infiniti to a Nissan now
This week I am going to just push the cross bars as close to the middle as possible and leave them there (least resistance to wind flow up front and deflection in the back). Additionally, I will try the 89 octane as in the other thread to see if it helps me in any way.

[PathyPop]

To maybe save .5 mpg you could remove the fan/clutch assembly and install an electric fan/thermostat. Would be an interesting experiment for not much money if you pulled one from the salvage yard.

[brickbox]

Are they electrical fans that would just bolt up? If its a straight swap, then I might try this once it gets warmer for the 0.5mpg. If its going to take a whole of cussing and fussing, I am going to try the low hanging fruits first before I get to this.

[PathyPop]

I only lightly looked into it. There are a few threads about it here and on youtube, etc. Specific Ford Taurus and Maxima fans were discussed as fitting. Getting a fan from a pick your part salvage should just be a few dollars. Still, new ones are less than $100, even some dual setups.

Some say it will improve 1 mpg, some say zero, so I'm going with .5 mpg. Still, thats ~3% or 10c/gallon. So could pay off in a year or two. Getting the old fan/clutch out also makes more room in the engine compartment.

[brickbox]

Gotcha! I have this bookmarked. I might give this a try when the warm weather comes around.

[Mike W.]

I too have heard good things about the Taurus fans, but in the BMW world where I mostly reside. I did do an aux fan in front of the A/C condenser, but I don't think it's up for cooling the engine by itself. There is a spot in the fusebox for an aux fan, but no wiring to go with it. Still, it was handy for me. You'll have to buy a fan controller and figure out where to set it. My primary intent was more cooling with the A/C on so I wasn't too worried about the calibration since it comes on with the A/C.

If the fan clutch is working there shouldn't be much gain though.

[PathyPop]

Looking into how the fan clutch works, I read that you should be able to spin it by hand and it will continue 3-5 revs. Mine has noticeable resistance and doesn't make it even one rev. This inefficiency, along with the mass of the clutch always turning could make sense for an electric fan. Ours has the typical cracks in the fan hub that they all seem to have too, so maybe we'll do it instead of replacing the oem fan.

[brickbox]

Looking into how the fan clutch works, I read that you should be able to spin it by hand and it will continue 3-5 revs.

I will give this a shot hopefully sometime this week and see how if I have any different results.

Moving the cross bars from the extreme end positions (where they have been since I bought the car) to the closest to middle positions netted me about 0.4mpg.
Interestingly, I ran 2 tanks for 93 octane and did the exact same routes and matched my speeds within 2 mph (always under 75mph) and in similar weather conditions, I got an improvement of about 0.2mpg. Little disappointed. So I have switched back to 87octane. The engine was noticeably responsive on 93 octane but the marginal improvement in FE is not justified IMO for the addition 70-75 cents/gallon.

[brickbox]

I am reading the opposite of what you stated above.
If it is cold, the viscous coupling in the clutch will offer significant resistance. Once warmed up, the rotations are much easier. Mine seems to be following this.
All the blades seem in good shape and I didnt notice any leakage either from the hub.