Brushedpewter

whoops, I mean 3.5
I paid too much detail to the 04 that was in front.
Still interesting to see a 6 cylender in an altima. It will drive exactly like the maxima, only the altima body.

Matt93SE

iTrader: (44)

A while back, the same guys that did the RWD Alty did a VQ30 in the same car. (I think it was same car).

for the RWD setup, they stole the drivetrain and rear suspension from a dead 240SX and grafted it into the Alty. required reworking the strut towers and everything in the back. not a job for the faint of heart.

the VQ35 swap should be much easier, assuming you don't have to take a sledgehammer to the firewall to fit it in there. probably will, but just wait and see. good luck with the swap!!
might give me something to do when I finish my 3 gen Maxima and buy a new car for the wife. (she currently has a '97 Alty)..

And FYI, I know you don't care about stopping and turning, but those little Altys can handle fairly decent when modded and have good aftermarket options on suspension.. it could be a REALLY fun car.

Brushedpewter

The altima has plenty of space in the engine bay. I have seen the RWD altima, some website, don't remember now.

I own an altima. I'd love to own a max but a max would never make the 28mpg(hwy/city) I'm getting now.

JClaw

iTrader: (17)

MPG isn't bad. Just the highway RPMs that are too high. I blame our overly short 5th gear for that, not the engine.

NmexMAX

iTrader: (22)

Hi! Captain Obvious...

JClaw

iTrader: (17)

.

vsamoylov

a vq40 in a 4th gen.

nismology

iTrader: (8)

Which post are you replying to?

Brushedpewter

I don't even have a 5th gear. I'm sure my OD 4th gear is lower but I don't blame it on it. I blame the weight of the car. I mean come on 3000lbs and a 150hp motor, what were they thinking???????

99 SE-L

4 Th Gens had 190 HP buddy...

Matt93SE

iTrader: (44)

He's talking about the Alty, not a 4th gen.

Just an FYI, my 3 gen Maxima gets 30-32mpg on the highway if I keep my foot out of it.
my 5spd 240SX (with KA24DE) gets only slightly better mileage than my wife's automatic alty (with KA24DE). we drove the 240 and alty from here to Oklahoma when evacuating from the hurricane, and the alty ran out of gas before the 240. generally I'd add about 1.5 gallons less in the 240 than the alty at each fillup. I was averaging about 350 miles on a tank in the 240, and it comes out to just over 30mpg.

the Maxima will go about 475 miles on a tank before filling with 16 gallons.

Soooo, the comparison in mileage between the engines and gearing really don't make a whole lot of difference, IMO.

Weimar Ben

iTrader: (5)

I have to call BS on this one.

4th and 5th gen 5spd will not get 475 miles on 16gal (29.68) because of the $hitty 5th gear. The best I've ever gotten on my 4th and 5th gens is 27mpg and that was going 55-60mph. EPA est. is 26mpg on the freeway.

Anytime anyone claims a fuel economy figure that is significantly different than the EPA highway figure, they are FOS.

6spd maximas get 30mpg pretty easily.

Nissan doesn't give a rat's @ss about fuel economy. Nissans get the worst fuel economy in just about every category. Hell, even GM can squeeze 30mpg out of the ancient 3800 with the Bonnevile, Grand Prix, and Impala and those cars are heavier and require only 87 octane. You'd think that my 2900lb 4th gen could do better than 26mpg with premium gas, less weight, and a world class engine.

JClaw

iTrader: (17)

That's because most 4th gen really weight more than 2900 lbs. Mine weighted 3010 stock and it was still missing a few options. They say removing 100 lbs from a 3000 lbs car improves gas mileage by about 7-8%. I plan on counter-balancing that 5th gear with weight reduction (target is 2700, currently around 2870).

nismology

iTrader: (8)

My brother has gotten a little over 500 miles to a tank a few times in his 2k1 5-speed by cruising at 55 with the a/c off with almost all highway driving. Don't make an *** out of yourself by ASSuming it's impossible just because YOU haven't been able to achieve it.

Weimar Ben

iTrader: (5)

I'm not assuming anything.

The EPA tests brand new vehicles in laboratory conditions. Statistics and logic would say that it's pretty hard to do much better than the EPA test unless you do something like weight reduction, change gearing, etc. 30mpg in a 4th/5th gen 5spd is BS.

nismology

iTrader: (8)

You're forgetting about a few things though:

1. Chances are the motors aren't broken in completely yet.
2. It's a well known fact that older motors can actually have higher compression PSI than stock due to carbon deposits on the compression rings.
3. There is a greater amount of air available on a freeway than on a dyno which means a smaller throttle angle is required to maintain a given speed.

It's VERY difficult to achieve and require a STEADY 55 MPH with the a/c off and mostly highway driving, but it's possible.

Nealoc187

iTrader: (23)

I've gone over 460miles on a on about 16-16.5 gallons of gas in two of my three 4th gens, both cars multiple times...

choray911

iTrader: (1)

I wouldn't know, my odom hasn't worked in 3 years. I would have to estimate around 10 MPG because I'm weak and can't stay out of the throddle. On the hwy I cruse about 90 so that doesn't help either.

gameover03

apparently u didnt read the entire thread the SE-r we were reffering to was an altima....

Brushedpewter

EPA is a bunch of idiots. They don't even test the cars in the real world situations.

My altima gets about 31-32mpg on the freeway. But I mostly drive street so I never see that. Right now I get solid 28mpg driving mostly on the street and 30-40% freeway. Not bad for an auto.

If I drove 55mph on the freeway I think I can squeeze out 35mpg.

EPA for Auto 99 altima is 22/30

NmexMAX

iTrader: (22)

Since when did the EPA ever get that in a 4g?

Does this have any Maxima relation?

Weimar Ben

iTrader: (5)

I never said that it did. In fact, I specifically mentioned the fact that the EPA says 26mpg.

My point is that 30mpg is near impossible with a stock or near stock 4th/5th gen maxima with the 5spd. Add headers, catback, significantely reduce weight, syn oil, and then maybe you can flirt with 30mpg. Put in the 6spd like Vasily did into a 4th gen and you'll prolly be in the mid 30's.

The 5th gear is so crappy in the 4th and 5th gen 5spd that the auto gets better gas mileage. This is pretty amazing considering the fact that autos put less power to the wheels because of more moving parts, more friction, etc.

3300rpm @ 80mph is rediculous!! Hell, my buddy's accord auto 2.2L non-vtec is at 3300rpm @ 80mph as well and it has half the power.

Another example is the corvette and the camaro with the LS1. They get about 30mpg on the highway with a huge 5.7L pushrod engine with the 6spd. And my 3.0L engine and lighter car get 26-27MPG. WTF??

NmexMAX

iTrader: (22)

3300 80mph. @3k my auto is at 90.

vsamoylov

and that is where the 6 spd comes in.

Brushedpewter

I wonder how many mpg a 4th gen with 3.5 and 6 speed gets???

nismology

iTrader: (8)

Care to respond to post #56?

Weimar Ben

iTrader: (5)

true, but with the tight manufacturing tolerences of today, break in isn't really much of an issue anymore. The difference between a "broken in" vq and a new vq is going to be pretty marginal.

True again, but the difference in fuel economy will be marginal.


I don't understand what you mean by "more air" if the air pressure, temperature, and density is the same. Unless you have a functional hood scoop, I fail to see how this would make any difference.



With traffic how it is on the freeway, driving 55 where I live is dangerous. In a maxima, 55 feels slow as hell. I believe the EPA testing for highway mileage simulates driving 55, which most would agree is the optimium speed for gas mileage for most cars.

nismology

iTrader: (8)

If you knew what breaking in a motor actually meant, you'd realize that tolerances have nothing to do with it. The rings take time to be completely seated regardless of which motor it is. Ditto the main, rod, and cam bearings. While this process is taking place there is excess friction. And the difference is noticeable from a power standpoint.
You don't know that. Just like you don't know that it's impossible to get 500 miles to a tank. I'm just explaining to you how it's possible.
After more reading on the subject i discovered it makes no difference really if the car is actually moving or not. But my brother's car has somewhat of a CAI that's getting ambient air, so the temperature difference might play a role in it as well.If i'm not mistaken, the 55 MPH testing is a recent change and back around 2000 it was closer to 65 MPH. And does the dyno simulate the vehicle's momentum?


If you haven't noticed, the onus is on YOU to prove that it's IMPOSSIBLE, not us proving it possible. And thus far, you haven't quite succeeded.

Weimar Ben

iTrader: (5)

Sure there's more friction, but not a lot more. This extra friction and lower compression can be quantified. A new stock VQ30 5spd dynos at around 160whp. Brand new and stock it'll get 26mpg on the highway. If you can then get 30mpg on the highway after it is broken in, then that's a 15.4% difference. You could then conclude that after break in, it would then dyno at 184whp stock.

I never said that 500 miles to a tank isn't possible. I said that 30mpg in a stock or near stock 5spd maxima isn't possible.
500/18.5 = 27mpg. No, it's not possible to use all 18.5 gallons, but I have refilled my tank with 18.0gal before.


You don't need to simulate momentum in the dyno, what it simulates is the aerodynamic drag and friction. I think it's always been 55mph on the EPA dyno since gas mileage testing and the idiotic "drive 55" BS started at about the same time.

I can't prove it's impossible. It's just very unlikely and very hard to reproduce, especially over a long period of time. Same goes with time travel. No one can prove that it's impossible, but it is unlikely.


The way people measure gas mileage is subject to error. Here's the way people typically measure their gas mileage....

1. Fill up tank until the auto shutoff. The pump can do the auto shutoff when the tank is 95% full or when it literally starts coming out of the tube.

2. drive 55mph and measure the distance driven with the trip odometer.

3. Fill up the tank again until the auto shutoff stops the pump from pumping.

4. miles driven / amt pumped

As you can see, there every step is subject to error. You might overfill a bit in step one and underfill a bit in step 3. The pump itself could be off by a bit as well. At the same time, your odometer might be off a bit as well.

Let's say your odometer is off by 5% and the auto shutoff and pump measuring could introduce another 5% worth of error. I see a 5% increase in mileage after break-in as being plausible. So, 10% of error + 5% of break-in could explain how someone could "get" 30mpg.

Have a super smooth brand new road, a bit of a tailwind, and slightly downward sloping terrain, and you could get a few more MPG as well. You might get 28-30mpg with this, but that is in no way typical. I've gotten 28mpg before, but this is in no way typical for my car. Typical is 25-27. I don't run around telling everyone that I get 28mpg. I say 25-27.

nismology

iTrader: (8)

This argument between us started when i said my brother had gotten 500 miles from his tank a few times and you responding by saying 30 MPH is BS. In my experience, calculating miles per tank is pretty friggin easy. Fill up and drive until you need to fill up. Not that complicated. I never said he got 30 MPG btw.

As as for the method that you said most people use, it's flawed, of course. That's why most people that have sense use the same exact pump when calculating MPG. That eliminates the pump as a variable. Secondly, i doubt the odometer is off by enough to skew the numbers even +/- 1 MPG.

Momentum is very important in determining a car's fuel comsumption because it fights again the drag and rolling resistance. If the dyno doesn't take momentum into consideration before appying a final coefficient of friction value in the equation then the test is incomplete. It must, based on the vehicles mass, incorporate that into it's calculations. At least i would hope so...

Weimar Ben

iTrader: (5)

From what I've read, typical speedo error is +/-5%, even on a new car. If your speedo is off by 5% your odometer will be as well, which will skew your MPG calculation by 5% also. 5% speedo error would result in a 1.3MPG increase if your base mpg is 26.

Momentum is irrelevent in the test. You only need to calculate how much energy is needed to maintain the momentum at a given velocity to overcome aero. drag and friction.

Most people won't use the same pump when telling everyone about their crazy mpg figure. They'll get some crazy mpg figure when going on a long trip somewhere. I got 38MPG in a 96 altima once driving in eastern OR, but that was prolly due to the fact that my speedo was off by 6%, some pump error, and the terrain..

MaxGordon7

iTrader: (36)

its still better than nothing to at least know your mpg. It might not be right on but still gives you an idea. im always 20-23 summer, get 18-20 in winter. Show you i drive like a mad man.

nismology

iTrader: (8)

Then one could just subtract 1 MPG. It's not a huge difference.
Then it does not mimic real-world conditions. The vehicle's mass is as vital to determining MPG as anything else. Newton's 2nd law says so. Engine power isn't the only thing at work when overcoming aero drag and rolling friction. The car's mass is an integral part of how much engine power is required to maintain speed. Saying momentum doesn't matter is like saying a feather and a baseball would land at the same time if dropped off a building.

Weimar Ben

iTrader: (5)

a body will maintain its momentum (inertia) until acted upon by an external force. The external forces that determine gas mileage are aerodynamic drag, rolling resistance, and friction. When there's more mass, friction increases the amount of energy it takes to keep that same car in motion. So, yes momentum does matter but all you need to do is to calculate the amt. of energy needed to counter friction, rolling resistance, and drag.

Let's assume you have two identical cars with 2 differences. Car A has a mass of 1500kg and car B has a mass of 3000kg. Car B has magical zero friction wheel bearings and magical tires that have no rolling resistance. Car B will get better gas mileage, even though it is heavier. Car A will accelerate and go up hills better though.

sagamax

iTrader: (5)

ya i metsombody that did that too it was sick

vipervadim

iTrader: (10)

so can somebody please explain how getting 500 miles per tank of gas and a whole page of busting cohones between nismology and SR-71 Blackbird even remotely relate to Tilley's VQ35 Altima project???

thank you for whoring up Rob's thread, i though by the number of posts he got the beast up and running already

and next time start a thread in the general forum, no need to ***** up the ALL MOTOR forum



Hey Rob how's it going with the alty beast? can't wait till you get her up and running

98maximagle

I sold my 93 sissy-green auto altima last summer for $700 with 150k miles on it. Even with the 2.4L and auto, it was still pretty quick on a rolling start. Albeit that was against auto civics. My favorite part about the car was how well it handled even with the stock setup. Very predictable and a whole lot of fun in the snow. I can't even imagine how much fun it would be with the 3.5L! Good luck and keep us posted

NmexMAX

iTrader: (22)

Phrase of the day ...

JClaw

iTrader: (17)

Dude, auto civics are mad fast, I've seen one pull on an auto ls teg

doc2278

iTrader: (3)

Better yet, a vq 35 with the same mods on a big wheel......tell me your feelin it