what would you do?

[racerc2000]

Originally Posted by mcrews

You said:......"all in all its not that bad driving around town but on the highways it runs into an issue. I have no problem doing 70 ir 80+ but. after 60mph the aero kills mpg. cruising @ 55mph @1850 rpm the scan gauge would net between 24 and 26mpg. @70mph @2500 rpm it would be getting 12-14mpg :/ and by 80 its down past 9mpg."

you 'claim to have done research'........
not here!
or you would have NEVER made the comment in red!
So here we go.......
It's the gearing, not the aero that kills the mpg after 60mph.
And reading ANY of the 70 posts on the topic would help you understand that.
Engines have a sweet spot.
Hell, my car is very aerodynamic and I've done all the right mods. But if I go above 70 the mpgs go down!!!!
It's because the engine is turning too many rpms and is past the sweet spot.

search ABA testing.
go find a stretch of freeway and run at 50, 60, 70 & 80. establish a base line for your stock vehicle. run a/c on and a/c off.
log it by resetting the sg each time.
If you run tires that are 6-7% taller (read my posts) then you can see that your speed will increase for the same rpm.
And again, IF YOU WOULD READ, you'd see that we arent talking about .

tire to strut is not the only clearance issue with a car. assuming you are at stock height? and have no wheelwell clearance issues. or do you rub on tight turns but dont care?
jumping up from a 55-60 sidewall in my wheel size makes the tire go from 29-35lb. you do realize my stock tires are 27.7" right? and not a 24" I dont just have 18s and 40 series tires. my stock tires wouldnt even fit on your car so when it comes to the weight you wouldnt even understand.

and yes. even in drag racing when you cant go wider you go taller. but thats drag racing. ide have to go narrower and taller to keep a stock contact patch. wider and taller = larger contact patch and more drag. and try to find tires that will do that for 18s. or even 16s. (I cant place a wheel under 16" on my vehicle as it will hit the 11.1" brakes caliper.)

I may not be an economy guru but I know my cars and performance.

and apparently you have never dealt with a square vehicle? and gearing is not the easy fix for everything. any lower and ide be going 55 in 4th gear. 55 in 5th gear is hardly even giving it gas. you have to realize one small detail.

the older elements had a 4spd auto. and a 5spd manual. and the 4spd was fine to drive. the new 5spd auto is just the 4spd with an extra overdrive each gear and the final is all the same. they just added a .5xx after the .7xx so I really think the gearing and larger tires is far from an easy fix. dont get me wrong. if it was a 5spd manual with a .8xx 5th gear or the 4spd auto with the .7xx 4th gear YES it would be worth a shot.


does it look like a gearing problem?

apparently you've done some testing with your car and assume every vehicle is the same. if you would like me to prove to you that my vehicle has a crappy cd and over 60mph it gets much harder to force itself through the air I will.

hell if you dont believe me you can come visit and run the tests yourself.

@ 60+ it is so apparent the drag that I dont even need to use my brakes. let off the gas and it feels like im braking. and that is with a heavy set of wheels that wants to stay in motion not slow down.


clear enough for ya? I think its time you did more research...

[mcrews]

typical stupid statement:
"my stock tires wouldnt even fit on your car so when it comes to the weight you wouldnt even understand."

WHy would i want your tire on my car??? What purpose does that staetement serve? How is that relevant?
And don't get going on the weight issue. I'm the guy that explains moving weight being 4 times the static weight as a reason (to concider) in NOT going up on rim size.
But since you don't read.....you look silly.

ANd

"tire to strut is not the only clearance issue with a car. assuming you are at stock height? and have no wheelwell clearance issues. or do you rub on tight turns but dont care?"

Again, If you would educate yourself.......

OH DAMN!!!! WHO WOULD HAVE THOUGHT!!!!!!! with 255,000 miles, I wondered why there were rubbing noises!!!!!! You are so smart!!!!!!

Of course, there are other conciderations....duh........

AGAIN, If you were reading instead of 'dumping' you'd see that eco driving is very different from ricky racer driving.

Come on, you want to waste time on a windshiel wiper shield but can't have a conversation about tires!!!!!!
I mean really.......you act like a slightly taller tire is the end of the world......'lift kit'.....geezzz.
you telll somebody else to run motorcycle tires on a car!!!!
To say you have absolutely no understanding of eco modding.....
But I'm sure you'll have some quick reply..........

See what you are clueless about is after you post on a forum 1000 times, you see a pattern in new posters......
ANd you fall in to the catagory of noobies that don't read anything except what they post.

Hey, guess what......nobody else has an Infiniti Q45 on here either.
But I read and read and then asked questions.
And very early on I realized that this was a very smart forum that could teach me alot.
So I tried stuff and tested ideas.

So don't pull this "come and test my vehicle' crap.
Test your own car.

(see if you really had read the tire forums, you'd have seen Frank Lee's post about truck tires)

[racerc2000]

lets start by replying to your repeat post.

the point was a 5% larger tire when talking about a 25" tire is a big diff when talking about a 28" tire. esp in weight. for me it goes from 29lb to 35lb.

you are telling me to read when you dont read yourself? I can plus size my wheels all I want. and yes I know all about the removing 1 lb rotating mass is the same as removing 10lb static mass. (on a time slip)

im very sorry if youve never had the luxury to obtain well made wheels. so this may come as a shock to you. but yes. the 19" wheels I am replacing my 18s with are both larger 19X9 and 19X10 as opposed to 18X7. and the 18X7 weights 32lb where the 19s are 19X9 20.5lb 19X10 20.9lb. yes it is a substantial decrease. not like the people who jump on pretty wheels that endup weighing 35lb+ in large sizes. and Ive also decided on tires 245/45-19 that weigh 4lb less then stock and 275/40-19s that match stock weight of 29lb. but thats what you get when they are forged wheels made in japan strictly for the 370z spec S package.

the point being I already told you in my other post that tires were decided on.

as for rubbing. I prefer to have my vehicles in full working order and not having issues like rubbing. and im not that bent on economy to destroy my car in the process. rubbing means you screwed up. there is a right way and wrong way to do mods. as well as a cheap way when you dont care about the car. I happen to care about mine.

as for the transition of the windshield to hood. you dont need better aero in that location so its expected you wouldnt know about it or suggest it to anyone.

and if you read my post you would see I did run tests already. and you believe me to be wrong. so "if you dont believe in my tests, your more then welcome to test it yourself"

Im not looking to convert my car to an economy car. Im looking to reduce some cd to reduce the velocity/drag limits. maybe an extra 10mph. and at the same time it will increase economy also.

and yes eco driving is much different then racing but. the fundamentals of a build are very similar. the biggest diff is in how you drive in the end.

[mcrews]

i said:
OH DAMN!!!! WHO WOULD HAVE THOUGHT!!!!!!! with 255,000 miles, I wondered why there were rubbing noises!!!!!! You are so smart!!!!!!

Of course, there are other conciderations....duh........



you said: "as for rubbing. I prefer to have my vehicles in full working order and not having issues like rubbing. and im not that bent on economy to destroy my car in the process. rubbing means you screwed up. there is a right way and wrong way to do mods. as well as a cheap way when you dont care about the car. I happen to care about mine.

Ok....follow......
I was MOCKING THE SILLINESS of your statement........
My tires dont rub....duh......


It's an Infiniti......
you drive a honda.......
Don't talk cheap to me

Again, I knew you'd have a quick unthought out reply.
Back to the point.....read.
Why do you want to debate me?
quit proving the kinda of noobie we KNEW you were going to be......

[mcrews]

Fatter wheels and tires do not reduce cd.

[Tesla]

Why all the heat, just chill out a bit.
It is always a compromise, how far one goes with this process, there are always other factors at play.
You need to remind yourself that, ecomodding itself is a compromise, remember you'll never match the economy of those guys on pushbikes.

So your tyres are decided, so with new shiny wheels then wheel covers are out of the question I suppose.
Are you going to evaluate a new baseline before going further, or just go with the build up?

[Ladogaboy]

In this case, I can just tell you what I DID.

Start tracking your fuel economy and logging it with the garage tool on this site.
Read the hypermile driving techniques and start to "adjust the nut behind the wheel" as people here like to say.
Ensure that your car is properly aligned and your tires are filled to max pressure.

Consider some of the modifications you might eventually do by reading as much as you can in the Ecomodding/Aerodynamics section, but hold off on doing anything that costs money until you are reasonably certain that it will pay for itself.

[Ecky]

The cd of the Element, from my google-fu, seems to be in the range of 0.35 to 0.40 - lower than I'd expected. With the huge frontal area it's going to have a huge impact at highway speeds for sure.

Definitely do the belly pan and grill block and report back.

[racerc2000]

Originally Posted by mcrews

It's an Infiniti......
you drive a honda.......
Don't talk cheap to me

Again, I knew you'd have a quick unthought out reply.
Back to the point.....read.
Why do you want to debate me?
quit proving the kinda of noobie we KNEW you were going to be......

Fatter wheels and tires do not reduce cd.

I dont remember ever stating that fatter tires would reduce the CD...

dude you drive a 250k mile 02' I drive a 2010 with 13k miles. you do realize one small detail right? in japan the origin of our cars infinity doesnt exist its NISSAN the same with acura/honda and lexus/toyota. its just a trick to make you feel you bought better.

if I did not have to transport a wheelchair and prefer a tailgate for the ramp. and I had another option in 2010 I would have taken it. but the landrover lm2 was already dead by then as a new car.

is there a reason you are debating with me about questions I didnt ask?

sarcasm and typing coming from someone I dont know... no need to get bent out of shape and reply so much.


So your tyres are decided, so with new shiny wheels then wheel covers are out of the question I suppose.

wheel covers would still be game a pizza pan or simmilar some foam tape and some flat stock to hold from inside the wheel. or. for the larger wheels they have a smooth disk similar to the cleanwheels but with no vents.

wonder what the diff would be open, sealed inside, sealed outside.

I shall reevaluate my baseline before new mods.