Entry Level Luxury Performance Sedans

pgill

I own a G35x and the gas mileage is one of my biggest disappointments with the car. I have a long commute with 80% highway driving @ 75 - 80 mph and I have been averaging 20 mpg. I have over 8,000 miles on the car and I followed the break-in procedure recommended by Infiniti. There are boards dedicated to Infiniti and Infiniti G35 where other owners have posted their experiences with respect to gas mileage...perhaps those would help. You can email me if you want the sites.

blueguydotcom

...but matched with Nissan's gearing, man does it gobble gas. Add in the weight of the AWD system and it's not a shock mileage is so bad.

chrisboth

The non awd gets about 22 until broken in then about 23-25 on hiway. Not much better and the awd system is very effivcient and maybe another 180 pounds looking at the weights online (6 mos ago anyway).

Like I have said - get the crawford Z plenum and up that by 3-4 mpg - I get about 28 on the hiway.

Also you aren't bnroken in until about 15k ..people are finding improvements are coming in big surprising doses well after a year of ownership.

dhanley

Several friends who have g35's get low twenties, and this seem consistent with online reports. Expect AWD to cost about 2MPG or so.

A plenium getting 3-4MPG improvement is pure snake oil. No one with a lick os sense is going to buy that... A car cruising on the highway has the throttle at high restriction anyways, so less restriction in the intake obviously isn't going to help.

I'm not sure how much the stick shift is going to help MPG, but if you're interested in a sports sedan, this is obviously what you're going to choose. Otherwise, save your money and buy a buick.

chrisboth

Well enjoy the taste of snakeoil since all your friend get low 20's and I get 440 miles on 1 tank not going below E. DO you even know what a plenum does einstien?

blueguydotcom

Sorry every person I know with a G35 nets 22 mpg or lower. I mention getting 30 on the freeway and a friend with a G, his eyes light up. He's delighted if he can eek out 24 mpg on a freeway trip to vegas.

dhanley

Yes, i do. Wide-flow plenums sometimes do increase high-end power, especially when turbos or superchargers are involved. But when throttle is mostly closed ( as when a 3.5L engine is noodling along on the highway ) and vacuum is high, increasing airflow to the engine obviously isn't going to drive MPG way up.

To quote the ednumds test:

"We're also unsure as to the fuel economy outlook with the all-wheel-drive system, as our test vehicle averaged only 15.4 miles per gallon while in our care."

"and I get 440 miles on 1 tank not going below E."

The g35 has a 20 gallon tank. 440/20=22MPG. So that means you get maybe 23MPG? You're still doing better than other people i know. My 7+ year old BMW with a 17 gallon tank has gotten over 550 miles on a tank.

dave

chrisboth

http://www.kptechnologies.net/chris/chris_race.htm

Proof is right here in terms of power increases anyway.

Try again with real math. Since I wont brave using the 5 gallon reserve I fill up at E on the nose. Let's be conservative and say that there are 4 of 20 gallons left so 440/16=27.5. Pretty good and obviously there is better math with a fillup for actual gallons.

The stock plenum is choking the front bank of cylinders for air. A less restrictive plenum doesn't allow for more air it allows the SAME air to work more efficently by more equally sharing the airflow and distribution of that airflow. Lots of people doubt this snakeoil plenum adds any power either and thats why enthusiasts race and test and race and test and the rest of the daisy drivers wonder and live with things the way they are.

I didn't get from 15 to 14.2 in the quarter mile with twin turbos - a pulley and a plenum is all it takes. $750 total

chrisboth

PS can your 7 year old BMW keep up with a golf?

dhanley

Nope. Those guys have magnets that polarize their fuel and double their horsepower--made by the same guys selling you your plenum and pulley.

dave

chrisboth

I noticed it's the beemer guys who doubt this the most. Just like the coupe guy did until I schooled him on the ways of Crawford Z engineering - noe he sports one too!.... enjoy your 318i. :0

Putting new design plenum on G35....$390

Consulting with several memebers of dedicated website for 12 months and running dynos to verify results while consulting with engineer....$200

Airmchair racing and armchair engineering that conclude diddly: PRICELESS

dhanley

Like i said, anyone who understands how engines work is not going to be fooled by this--even the crawford Z web site says that the plenum only makes a difference (adding horsepower) at high RPM's.

Since you already inadvertantly admitted getting ~22mpg in your buick(autotranny) g35, i don't know why you're getting so excited about this.

speedracer3

My Maxima did terrible gas mileage ~18 mpg, but then again I didn't get the car for its fuel economy. I wouldn't expect the G35 to be fuel efficient, I would just enjoy the performance at each fill up.

My A4 gives me the best of both worlds though. I get fast reflexes and 26 mpg. Couldn't be happier.

chrisboth

I inadvertantly admitted this exactly:

"The non awd gets about 22 until broken in then about 23-25 on hiway. Not much better and the awd system is very effivcient and maybe another 180 pounds looking at the weights online (6 mos ago anyway). "

Your reading comprehension must be better than you allude with your argument. 23-25 is not bad and the math works out if you get out your calculator and concentrate.

Anyone who understands how engines work would recognize the value of having all 6 cylinders get equal airflow. You may not believe it but most used car buyers wishing they could even keep up with the last generation camary are not worth convincing.

Horsepower added at higher rpm's is a sypmtom of the greater efficency. If you believe the plenum helps HP then what is your explanation for why hotshot? Whatever your answer it can be applied to the fuel efficiency argument so you must believe two contradicting things...not worth the time anymore but fun during a meeting that is over...come back if you get a real car and want to learn something

dhanley

That's just not how it works. In situations where the throttle is wide open, airflow is an issue. At low RPM's on highway drives, there is a high level of vacuum in the plenum already, and airflow is slow--nothing is going to get starved. Even the developers of the plenum say this. I know you unfortunately can't cope with a manual transmission, but there is a thing on the dash called a tachometer that will help you see highways RPM's.

By the way, if by getting our calculator out and concentrating you conclude that 440/20 = 23-25, then i see why we're having problems communicating.

dave

sweetc230

I'm averaging 18mpg in the city (aggressive driving of course) and on the highway this past holiday weekend I averaged 26mpg!!! I was blown away. Keep in mind that my '03 G35 coupe is used and has about 25K miles; so this could support the argument that the gas mileage gets better with age. But 26mpg is definitely surprising for a car like this. Just my .02 for what its worth.

chrisboth

I suggested that you get the calulcator i work with numbers all day. Just suggest you follow along since you mis-quoted me. Also while you drive your 5 speed and think everyone else that has an auto can not, remember that you are special and people really do like you even if you aspire to own a camry.

When I need a manual I can always turn to the real speed demon the zx-11 ninja. If you need schooled on shifing I can teach you, but I'd have to charge.

And while you're at take some classes on engine design. Bolt ons are one thing...fundametally changing the intake is another. You babble about throttle positioning...who cares...what matters is the SAME AIR (please dont repsond until you get this) is more evenly distributed. Stop choking the front 2 cylinders and you dont need to open the throttle as much whether there's a vacuum or not.

I'd be jealous of G owners too - we are having alot of fun. Save up and you can have 300hp someday too.

cheerioboy26

I have 28K on my 03 G 5AT sedan. Overall mileage is 19.4. Not sure what % of total miles are city/highway, but driving 70-75 mph on I-95 will get me 24-25 mpg when the traffic allows. Driving all-around town in the cold DC winter gets me only 17-18 mpg. This time of year I get around 20 in about 80% city driving. EPA is 18/26, and considering the "26" figure is attained by never crossing 60 mph on the EPA test, my numbers seem realistic.

pgill - EPA AWD figures are 17/24. 20 mpg doesn't seem all that bad at 75-80 mph. There's no way you can expect to get 24 mpg at that speed, given the way the EPA comes up with their figures.

dhanley

Cute little insults. I'd better start working lots harder so i can afford a less expensive car.

dave

chrisboth

Right beemer buyers insist on paying more! Look it's been fun - reacting to someone who's got no real contextual experince to draw from teaching those who have it based on your so called knowledge. You didn't expect a boquet?

I wouldn't be so adamant about things you know little about in real world context unless you like abuse. Reality speaks volumes and theorizing is a waste of the modders time.

You didn't pay G prices for a 328 did you? Hopefully you just didn't update your profile and you have a 540. Then you'd be able to hang!

dhanley

Sorry, but when i see people making up facts they have no idea about, i like to respond. Other people have a right to get rela information. I expected you'd be upset to have your little bubble burst, but there ya go. Even the salemen for the plenum don't make the claims you do--they'd get sued.

Still, it's flattering you've declared that you're done talking to me three times already.

And, yes, i only have dreams of being able to hang someday.

chrisboth

You should be flattered LOL. I have a special place in my heart for BMW fans. ACtually its my desire to make sure there IS real info on here regarding the G as many many people misinform here.

No crawford doesn't sell based on milage - it more for HP - he quoted 15hp did he not? You pretty much abuse the notion that the thing helps fuel effeciency what is your explanation for 15 HP?

You know I could care less about mileage - just reporting about my results _ i was surprised too. I bought it and am happy primarily from a power/repsonsiveness standpoint which is evident on the video. I think people looking for good info have proof in my video pudding. You again are left wanting with unproven theory or a desire to be heard.

Maybe you would theorize I get better milage becasue I floor it all the time...? Maybe the plenum sucks and the 500 or so people on G driver.com really got better gas mileage from the break in.

You come up with something more concrete than your proclomations of baseless never been there theory and I will listen and learn...as I always do when giving my baby the best I can. Again your argument whether focused on power or fuel economies is pretty much been "it doesn't work that way". Look at the video...thats all plenum and it rocks whether you can deal with it or not.

dhanley

Aww, i'm blushing that you keep responding to me.

" You pretty much abuse the notion that the thing helps fuel efficiency what is your explanation for 15 HP?"

I already explained that. Plenum restriction does have an impact for high RPM wide-open throttle operation. This is normal and expected. There are lots of dyno graphs that illustrate this--often airflow enhancement hurts power at lower RPM's. Counterintuitive, but that's how it works.

I found some interesting g35 dyno charts with the crawford plenum, but unfortunately i can't link to them due to town hall rules. According to them, even 15hp is optimistic. But i'm not arguing about power, just the idea that increasing airflow is going to incrase economy. It just doesn't work that way. Your engine is *SUPPOSED* to be starved when cruising on the highway. That's the point of a throttle.

A lot of people seem to assume that increasing one aspect of efficiency ( power ) is going to positively impact another aspect ( fuel economy ). They're often different issues--but not always of course--reducing internal friction would improve both. But thinking that anything that increases power is going to increase fuel economy is like thinking that anything that helps me run faster is also going to help me bench more. Not necessarily, or even often, the case.

dave

pat

Uh, it's probably time for the two of you to agree to disagree and move on. Neither of you is going to convince the other and there is no reason to let this petty squabble overtake this conversation.

In any case, knock off the personal digs.

Thank you.

Kirstie_H

A newspaper reporter is wondering if people are satisfied or dissatisfied with their vehicle navigation systems. Please send your brief comments and daytime contact info to jfallon@edmunds.com no later than Wednesday, July 14, 2004.
Thanks,
Jeannine Fallon
PR Director
Edmunds.com

cdnpinhead

a wonderful thing. Bliss is involved, as I recall.

Anyone who understands thermodynamics, gear ratios and aerodynamics won't be especially surprised by what's happening with the 3.5 litre Nissan engine.

On May 24th I posted the following. It may still be relevant:

"Well, it's interesting to see that there's yet another board in which the laws of physics and thermodynamics have been repealed.

Is the premise here that some bolt-on outfit has figured out something that the Nissan engineers either: a) were too stupid to see, or b) found, but didn't want to use, because they didn't want the engine that they use in 90% of their vehicles to have more power and/or fuel economy?

It's a conspiracy, I tell you! Isn't "big oil" involved somehow?

P. T. Barnum lives!"

blueguydotcom

I bow down to that post. Excellent.

saugatak

I've had my issues with dhanley before, but I think he's right on the plenum.

Chrisboth, if you're getting 440 miles on a full tank of gas, you're averaging 22 mpg, which does not indicate a gas mileage improvement for the plenum.

m4d_cow

which one does better in insulating heat?

btw does anyone know where to get the v-kool in the WA area for my car's windows?
I know they use v-kool for office windows sometimes in uS, but here in US i havent heard of anyone using it in their cars, while a lot of people use it for their cars in Asia and Europe.

chrisboth

"Chrisboth, if you're getting 440 miles on a full tank of gas, you're averaging 22 mpg, which does not indicate a gas mileage improvement for the plenum"

Like most I do not go into the 5 gallon reserve. I get filled up on E and typically my fill up is about 14-15 gallons - NOT the 20 in your denominator. The plenum theory is certainly unproven but the mileage results are facts for many people. I agree with the vacuum thing and all the other talk about highway airflow needs not being great enough miss the point regarding inefficient cylinders. Starved for air is one thing...never getting what the others have ever is another. Hi rmp whatever...im always in high rmp - maybe thats why my results go against all the proposed theory. In any case Im running a faster car than a magnum 300c or a 540i...that's what I bought it for. Power and repsonse. All the mods I have performed have given me better gas mileage in incremental and distinct blips right along with additional power. Perhaps Dhahnley is right and the break in is responsible for my 47% improvement in fuel economy. Anything is possible but for those laws of physics seem to be working in my favor.

Coppenhead - watch the video and then take some physics classes at your local communinty college bud. 14.2 seconds wont be attributed to my driving skills or light weight. Oh right it's the break in. .)

fjm1

Chris: you can lead a horse to water but you can't make it drink.

I believe auto manufacturers intentionally sandbag cars so they can easily incrementally improve them.

I believe auto engineers are people and can make mistakes.

I believe that some enterprising and ethical after market engineers can boost vehicle performance.

I believe in ghosts but not aliens.

But if there were aliens they would be our intellectual superiors. They would drive G35 because they kick [non-permissible content removed]. Especially with a Crawford plenum. Yoda would insist that his white G35 be suitably plenumed. "To hades with the warranty" he'd say as he laid down 6 inch longer strips of burnt rubber with the massive 10 pony power increase. Yoda would stop by Chewy's house and they would cruise down to Roswell, New Mexico for a class reunion getting a hefty 2 mpg increase over stock.

Darth would definitely show up in a black BMW 330 talking lots of smack to Luke about coming to the dark side. "Zeh gerrrmans haf wayz of making carrrrzz, Luke" Leah's skimpy outfit would interupt the conversation only because she doesn't look so good in it any more. And so the social posturing would continue, the grog would flow, and eventually light sabres would be drawn.

Cut to chase scene involving the big bad BMW getting smoked by Crawfordized "Using the Force" G35. Good guys win. Bad guys end up being your father. And I need to lay off the sauce so early in the morning.

chrisboth

may the scwartz be with you

blueguydotcom

I still think Uncle Owen should have sold Luke to the Sand People.

And Han's STi can cook all of them. She may not be pretty but she's got it where it counts.

designman

"I believe auto manufacturers intentionally sandbag cars so they can easily incrementally improve them."

Porsche is great for this.

Stop belittling yourself with the "lay off the sauce" crack. Creative writing is a good thing. It's one of the best aspects of the net and not enough people appreciate this. Nice job.

riez

Euro. Inc. would bring over their wonderful diesel and turbo-diesel engined cars. The European press raves about cars like the 330d. MB is bringing over the E320d. Great torque and outstanding fuel economy. Can't wait till USA gets the low sulphur fuel! Now if only EPA and enviromentalist activists in USA would advocate for diesels like their European counterparts!

speedracer3

How did this converation degrade from plenums to Star Wars?. I reiterate my thought, I don't mind doing mods but I would stay away from the kind that would void my powertrain warranty.

The power of the dark side is luring me to chip my 1.8T, but I will resist.

m4d_cow

i dont really get this, why the diesels? Of course its low on fuel consumption, but what else does it have?
i tried 330d when i went to aachen to visit a relative, its a great ride, doesnt feel like a diesel, but otoh its slow and underpowered.

brightness04

People always idealize what they dont know.

chrisboth

...or deny what they can't understand...

blueguydotcom

From what I've read it's a 7 second to 60 car. Not lightning but for over 35 mpg with cheap diesel fuel (savings over 30 cents a gallon), that sounds mighty tasty.

If someone other than VW made a diesel for CA, I'd own one right now.

designman

"How did this conversation degrade from plenums to Star Wars?"

You call that degradation? Here, try this one out…

Beavis: Hey Butthead, what’s a BMW?

Butthead: I don’t know Beavis, but I heard it sucks… u-huh… I hate things that suck… u-huh.

Can’t help but wonder which car brand has the highest percentage of Beavis & Butthead fans. Can’t you just see them coming back someday, “mature” and riding around in a Z4?

;-)

cdnpinhead

a 1.9 litre turbodiesel rental four times in Europe (Audi 3 times, VW once), and was stunned (the first time) at the low-end torque and general good manners of the engine. The thing accelerated wonderfully.

They were all quiet and got 35 - 40 mpg (all conversions done carefully) through Austria & Switzerland (serious mountain passes) and Germany (cruising at 90 - 110 mph).

Given how well the 1.9 powered the A4 & Passat, a 3 litre would be that much better. I'd buy one in a heartbeat.

blueguydotcom

Hmmm, suspect logic.

fjm1

Can’t help but wonder which car brand has the highest percentage of Beavis & Butthead fans.

Easy one, Chevy.

"How did this conversation degrade from plenums to Star Wars?"

Like it could have gotten any worse. That's like saying we were already at the bottom of the well and kept diggin'

More diesels would be a good thing in the U.S. They get good hole shot because of the torque. Dogs up high though which has always made me wonder why the Germans like 'em. Guess for fuel econ.

Heard Jeeb Liberty is coming with with a diesel. Doesn't really help entry level lux sedan though. Mercedes should definitely get on the stick with diesel in U.S. VW too.

dhanley

Yes! The main reason i haven't gotten another vehicle yet, despite earlier ovservations that my panhandling venture is not going well, is because i am awaiting a more eco-friendly, not-forcing-foreign-foreign-oil-dependance sport-luxury vehicle. I suspect i could average (city/highway mix) 35mpg in a 330d which would be awesome, and it could burn vegetable oil in the process. A friend rented a c320d in europe, and he acheived 35mpg averaging 100mph on the autobahn.

chrisboth

Anyone see the pics of the Nissan GTR concept pics in Road & T? Damn and supposedly will be matching the new m5 in performance specs or shooting for it as a benchmark anyway. 2007 will be a great year to buy a car - and it prob won't be from all the diesels or hybrids out there.

By then we'll have the v-10 M5, the GTR, the m45/35, a 6.0 litre hemi or something in a souped up 300C (next year i think), the audi rs6 redesign and the 3 series with a turbo or v-8 (kd?). Then we'll have to rehash all this again!

And we better start drillin in Alaska - these things are gonna suck fuel like I drink Sierra Nevada...

pat

Hmm, it seems like I should probably make mention of the fact that lots of these recent posts don't have anything to do with the subject of our discussion ...

saugatak

Like most I do not go into the 5 gallon reserve. I get filled up on E and typically my fill up is about 14-15 gallons - NOT the 20 in your denominator.

Are you sure you're holding 5 gallons in reserve? Because then you're averaging nearly 30 mpg?!!

That's pretty unbelievable mileage out of the VQ, which is a pretty thirsty engine.

chrisboth

No not sure that's why I used 4 in my denominator. These cars have huge reserves. I never go to E usually let alone below. My biggest fill up ever was 16.6 gallons. it holds 20.

designman

Alright... all you young whippersnappers... eat a granola bar and let's stoke it up around here.

Saw a new G35 coupe billboard on the NJ turnpike... very simple... shows it in full profile. The headline said simply "Pure". Indeed it is. Some guy in the building where I work has one. I always find myself ogling it. Needless to say, the look has grown on me. It's just so smooth and looks bolted to the road. Wish the front end looked meaner though... kind of looks like a droopy-eyed smiley face. And the headlamps sort of resemble witches' fingernails. Think I could live with this although I wish these car manufacturers would nail things down from head to toe.