Fuel Consumption 4speed vs 5 speed auto's

[Slinky-minky]

hey wanna know how much difference there would be between a 4 speed transmission and a 5 speed auto trans mainly in the final gear on a highway. have looked at gear ratio's but the 4th and 5th gear respectivley have about the same ratio .72 or so. the only differnence is the final drive gear ratio which is heaps different so i know 1 is more economical than the other but it looks like the 4 speed is more economical because the final gear ratio is higher, so does the 'final gear' come before or after 1st gear, 2nd gear etc???

thanks
chantalle

[silverGPX]

get an fto with a 4 speed more parts for it if i breaks. most ftos fuel consumption if driven normally is about ~600kms

[Astron_Boy]

Get a 4spd, simply because it's far less headaches later.

Or a manual!

[Kustom]

Get a 4spd, simply because it's far less headaches later.

Or a manual!

This

[vipfto]

Yip Manual FTW

and Simon before you say it HTFU

[Slinky-minky]

Thanks for the help guys!
I'm not a big fan of manuals, not because I don't know how to drive one, (because I do I was taught how to drive in a manual Lancer.) but because of the convenience factor!

I am a very busy person, as most people are these days. I do not have to waste, so if I am doing something I will always do something at the same time, such as folding laundry while watching tv, watching tv while on the internet or eating my dinner while I am driving, manuals tend to hinder my multi-tasking while driving, also this is even more annoying if you are driving a car that has the indicator on the left of the column, because my left is my shifting and indicating hand, which isn't to great for roundabouts. ?

Surprises- Manual is also a little annoying in the case of a kangaroo bouncing itself out in front of your car. My instinct in an emergency is to go straight for the break to avoid hitting the Roo, child, car ect or finding a path around it, not going straight for the clutch.

[Astron_Boy]

manuals tend to hinder my multi-tasking while driving

Really wish I hadn't read that.

But I will hold my tongue and hope sense finds direction.

[brent88]

manuals arnt always faster even though some people might think this.

manuals lose less power from transmission estimated at 5% (loose 15%through fwd, 20%rwd and 25+ through 4wd, did read this on a reputable site but dont know where it is) obiously averages of generally good condition exapmples maybe 5-10 year old. but when u drop the clutch everything is jolted into place and the 'shock factor' comes in to play and ussualy results in wheelspin obiously reducing the revs will stop this but then your sacrifincing takeoff speed)

auto's lose 5% avg power over a manual but with the fto's u still have the availibility to shift whenever u want (i ussualy shift at between 7 and 7,800, i love it when the second cam takes over pretty sure its higher rpm then the best shift point. and with an auto u can 'preload the transmission' by holding your foot on the brake revving the car (i use about 3,000rpm) and letting go and slamming the accelerator pedal down at the same time. can take off at higher revs and ussualy will compensate for the power loss in even a quater mile where an fto should at least reach 160kmph stock.

i know im probably gonna get blasted (mainly by people that go by what 'their fully sick mate' told them so ill try and find a few references i guess) btw im pretty sure the best drag cars in the world use automatic transmissions.

also i think (correct me if im wrong) but the 5spd tip has lower gearing that could make better use of the gears making it a closer ratio gearbox....? its supposed to be not as bad as somepeople think but obiously more than a few seconds preloading will b bad (i do it at some giveway signs if traffic is heavy never had problems with 5 years of driving auto's, have had manuals though)

http://autorepair.about.com/library/glo ... f-030a.htm
BigM
05-13-2005, 06:46 PM
Nearly all real drag racing cars are automatic or slap stick. It is just way more consistent. If you are bracket racing it is easier to load up the TC and launch then try to dump the clutch perfectly.

Yes in theory the stick shift will put more power to the ground but if you can't drive more power won't help you that much. Also in a 1/4 track you might be faster if you have an auto that is still ripping along in third as you hit the lights vs. having to shift to 4th gear in a manual.

So there are lots of things to consider beside just the transmission. Most drag cars are highly modded and have plenty of power regardless of transmission. A solid auto with a good torque converter and a shift kit will be consistent.(FROM A 350Z FORUM)

[brent88]

that was just the power side of things which dosent matter to chantalle

i got hungy jacks today and learned to appreciate the 'D' haha, remember when i had a manual and eating on way to work was near impossible.

The question is about fuel consumption between 4 spd auto and 5 spd auto

heres a site that gives u the exact gear ratio's of all the box's

http://www.mivec.co.uk/performancedata/index.htm

(and heaps of other info thats hard to find even if u have the manual like me)

[Astron_Boy]

Thing is to keep in mind Brent is that the average motorist that does commute driving will have far different fuel economy readings to a drag car.

Typically a manual will consume less petrol than the equivalent auto simply due to laden weight and the requirement for the auto to be a bit more hungry with the engine in grabbing the power.
Whilst more cars these days are going auto, I think it's more from a consumer stand point, if you look at most compact cars who aim for miles/ gallon, you will find they are typically manual.

Whilst the 5spd, though I am 100% unsure, may use a bit less fuel than the 4spd on highway driving with the extra gear, It MAY use more in the city as its shifting more, and therefore braking is altered.
Also the reason why a 5spd FTO is advised against is namely as there are less in the country, As being a 5spd owner, you do not want to have to find parts, mounts, shafts, diff, gears, tcu, anything to do with the autobox is different to the 4spd autos.
And there are plenty of 4spd auto in aus to get parts for at less cost.

In the end, a manual is better, but if auto is prefered or required, then go a 4spd.

[brent88]

my car only seems to get 400km a tank.............. besides my driving style and some other factors wonder what could b chewing my fuel,

maybe blocked cat or somthing, injectors are fine have disconnected battery so engine ecu loses memory, all wheel bearing are a1, driveshafts are a1, tyers are under 2000km old and have a lot of rubber on em, fully synthetic engine oil, think its 40/10 oil, new ngk iridium dx plugs(these are good yeah? cost me enough), prob has 30kgs of extra audio equiptment, sunroof(weight), CAI and pod?????

i dont know maybe i just need to retest

ideas??

cheers
brenton

[Slinky-minky]

manuals tend to hinder my multi-tasking while driving

Really wish I hadn't read that.

But I will hold my tongue and hope sense finds direction.

I honestly don't think that it's that bad, if it came down to avoiding an accident or dropping my drink I would just drop it, plus I always use a straw, this means I don't have to take my eyes from the road at all.

I am quite a sensible driver, I rarely exceed the speed limit and don't talk/text while I'm driving, not even with a handsfree, I always pull over. I have seen people multi task far more than what I do, it's not uncommon to see people in Melbourne doing their hair of make-up while driving, talking on the phone, checking their emails or glancing at documents while driving.

EDIT: If you're referring to the drop in power, I would just prefer to drive automatic due to convenience of not having to change at every intersection, more so when I am in the city and I am watching cars and pedestrians,I don't have to think about the manual, some would say I drive like a grandma, i think it's just being sensible so the drop in power doesn't bother me. As I said I was taught to drive in a 1.5 lt 02 Lancer that even being a manual is weak at the best of times, and my BMW is weak as hell anyways.

[Astron_Boy]

We've managed I think 650kms.
Or however much it was from Dwaynes and back.

Must be your driving style Brent

[brent88]

650...... thats good for any 2litre especialy a lap performance car, any ideas out of those things listed that could affect my fuel consumption that much?

[silverGPX]

i drove from toowoomba to maryborough and back 650km's round trip and drove around town a bit when i got back so around 680km before fuel light stayed on constant

This was with a fullboot approx 60kgs and the weight of a sub and amp, and a veilside front bar in the cabin, dont ask how i managed to get it in there lol. I demolished a veilside front bar on a really big hare at 140kmh a month beforehand, gotta love country highways at 12am, had to pick up the new veilside from maryborough.

But typically around town and the short 20km burst of highway to work i get around 550km/h. My fto is probably running lean haha.

I think when im old and cranky im going to be one of those people that gets a 4cyl car and puts it on lpg and drives 90kmh on the highway and whinges when i forget my 2c autogas discount and have a whinge at the servo. *shudders*

[brent88]

i hvae never driven it till the fuel light comes on, i drive it till its on the last bit before e, im scared of being stuck somewhere and getting laughed at coz im pouring fuel in my car outta a mower can.

a lot of hicks where i am even though theres over 100,000 people here, when my battery was flat coz the door light drained it while i was at work (11 hours) and car wouldent start and bonnet was up some dude i sorta work with yelled out 'thats what ya get for buyinh a cheap sh*tty import hahaha' i was pretty pissed off so i put dark mushroom flavoured soy sauce in his mug at work. haha that will teach him for being a ignorant bogan.

never heard about it again maybe he liked it? lol

[KJ_bob]

... sorry if this is said, but i can't be bothered reading the walls of posts.

Manual fto is more powerful then auto...common knowledge
Manuals tend to use less petrol... again common knowledge

btw pulled 750km out of my last tank... i don't usually run it that low, 500km is about as far as i let it get

[silverGPX]

lol regarding the fuel light, i normally have the "Ah, it'll be right", mentality.

Been caught out twice though in my old 1989 mazda 121 lol, i had to get a bunch of schoolkids walking to school to push me accross an intersection, they pushed me out into the intersection then let me stop in the middle, i was like "AHHH KEEP PUSHING!!" just got into a driveway intime. I find situations like that fun and thrilling, people get so embarrased!

[brent88]

lol yea thats a funny story but everyone woulda thought u were pov dumba*s for getting into that prediciment.

i remember this time (not gonna say if it was me) ******* and about another 4 guys got this harda*s teachers little hatchback and put it between two tree's (nose and rear end) with probably about 4cm room if that at each end (was a pretty good fit considering) woulda been fun to watch him get out of it, the thought if it reminds me of a common sight in melbourne.......... the 30 point turn haha

[silverGPX]

lol yea thats a funny story but everyone woulda thought you were pov dumba*s for getting into that prediciment.

Lol yep just got my red P's and was working $100 a week at eagle boys so their assumptions would be correct.