Info & question about gas saving w/4.11's

**Eganslp** · 03-21-2011, 07:03 PM

Hey guys, I was on my way to work and just thought to myself. Why dont I right down the rpms & mph that coresponden with it.
I'm currently running the Moser 9" w/4.11's and thought that this might be of some useful info. In which I'm sure this is prolly on here somewhere, but I figured I'd write it down anyway. B/c I think it could be used for a quick guide to my question also.
K, I was curious as to what rpm I could save gas in while driving around city w/4.11's. So here's what my car is running at with my rear;
Moser 9" w/4.11's:
Gear- Rpms- Mph
1st. 2k. 15
2nd. 2k. 21
3rd. 2k. 30 (*also 1'5k @ 19)
4th. 2k. 38
5th. 2k. 52 (*also 1'5k @ 35)
6th. 1'5k. 60
*usually when your cursing your not going past 60-65. Added those asterisks in there bc when I'm driven around in parking lots or school areas that's a good gear to stay in with a M6&locker. Anything else the car will jerk a lot.

I noticed today I could drive around the city streets in 6th @ 40/41mph @ 1100 rpms, but I'm curious to know If that is too low of an rpm to be driving around in. Now if I just lay my foot on the throttle it sounds smooth like it doesn't need much throttle to keep it moving, but if I were to just give it a tad bit more throttle then it sounds...... well..... sounds a bit like engine lugging to me. Now I'm not sure if that's what its actually called or not. Idk if i'm using the correct terminology for it. So plz correct me if I'm wrong.
So I guess my question would be; Is this a safe rpm to keep driven in at 40 mph? I just thought by keeping it in a lower rpm would help save gas.
Hope you's can help me out with this. Also hope this could be some useful info for someone wanting to go with a higher gearing but worried about gas mileage.
In which I forgot to add. My city I get roughly 159-170miles per tank & 225-245miles per tank on highway.

**TLS_Addict** · 03-21-2011, 07:13 PM

I think often times when you "lug" and engine and you use that gear to get up to speed you are getting worse mileage than if you down shifted and got up to speed more quickly and then put "back" in to the higher gear.

I tried to do it once with my 04 GTO and I cant say that it got better mileage either way but it makes sense to me.

**Demon_Z28** · 03-21-2011, 10:33 PM

I run 3.75's in my 9" and usually keep it in 5th gear around 35mph which I think is a little over 1,000 rpms.

Good question though! But honestly if you wanted gas mileage, you should have got a Prius lol.

**98maro** · 03-21-2011, 11:02 PM

i have 3.73s on my m8 i been thinking on getting 4.10s.. since im not driving it that much anymore, but waht can u guys tell me bout 4.11s or 4.10s?
is it worth it?
how do they fell on a pull on the highway?
thansk

**Eganslp** · 03-22-2011, 12:43 AM

@Demon that's not even funny!! lol I can't believe you even mentioned that word lololol Prius ?'s a Pri-us anyway........j/k!!! no I don't really care about the gas mileage I just figured if I can drive it right then that will help enough with saving gas right there. that's all I need. plus I was more worried bout the engine lugging or struggling to pull it's own weight If I put it in to that low of a rpm.

@ 98maro go with the 4.11's or 4.10's w/e it maybe you def. won't regret it. I love it!!! It pulls likes ravaged ape in heat with a jetpack on!!!! (lol) My quater mile was a 12.7 @ 113mph & i can't launch my car for shit, trust me!!! I got a 2.20 60footer. Plus this is my DD & I drive 24 miles to work and then back. It's a mixture between city/highway I get on average 190miles to a tank or filling up every 4-5 days and that's with me playing around light to light sometimes. I can't help it... it's an SS!! But If you can leave alil earlier and cruz. Then your golden dude. 4.10's/4.11s w/e it is, is the way to go im telling ya man. Im not tryna start anything by saying this, but I beat other SS all the time by a couple of lengths!!! LoL I tell them I just have Exhaust..... I just fail to mention that i have gears!! lolol but shh that's my lil secret hah!! Hey, if they don't ask I don't tell.

**TLS_Addict** · 03-22-2011, 01:23 PM

I would test something with my GTO and based on the "instant" mileage I found that if you lugged the engine too far you got worse mileage in a higher gear. I cant remember but if I was clost to 1k rpms I would make sure and pick a lower gear to get up around 1500 rpms. And the mileage did say it was better that way.

**Eganslp** · 03-22-2011, 09:03 PM

Originally Posted by TLS_Addict

I would test something with my GTO and based on the "instant" mileage I found that if you lugged the engine too far you got worse mileage in a higher gear. I cant remember but if I was clost to 1k rpms I would make sure and pick a lower gear to get up around 1500 rpms. And the mileage did say it was better that way.

yea thats what I do now the 5th gear @ 1500rpms its around 35mph. I guess when the speed limit goes to 40, I'll just say at 35(lol) but i was just curious if maybe I could get away with movin up one more gear to drop it down to 1k but forget it I'm not even gonna risk it.

**Too Fast** · 03-23-2011, 02:39 AM

So what is your actual gas mileage? Is your odo/speedo corrected for the gears? Those miles per tank seem awfully low....unless you are filling it when it still has 3/8 or more left.

**TLS_Addict** · 03-23-2011, 06:58 AM

Highway I would think he should still hit a minimum of low 20s because of that tall 6th gear.

**Eganslp** · 03-23-2011, 06:22 PM

Originally Posted by Too Fast

So what is your actual gas mileage? Is your odo/speedo corrected for the gears? Those miles per tank seem awfully low....unless you are filling it when it still has 3/8 or more left.

To be honest I have no idea. The gauge in my car is acting up. So I have to go by miles that I put on everytime I go to refill. Which is roughly anywhere from 159 to 175city and highway is like somewhere near 233 to 254 i think. but like I said up there somewhere I play around a lot and so....that maybe why I don't have the greatest gas mileage. I was only curious about gas saving if..... I had driven like a normal human being. Would putting it in at sixth near a 1k rpms be engine luggin thats all

I had calibrated the speedo with my Diablo tuner but it only gave me the option of 4.09's for some stupid reason and not 4.10's/ 4.11's w/e it is I have in there. I honestly don't remember!! I don't even know how to work the damn thing. Other than just using it for a code reader ... lol

**Too Fast** · 03-23-2011, 08:06 PM

I've used 6th as low as 1000 RPM, as long as you don't expect a lot, nothing bad will happen. The PCM knows the load/RPM/speed thing, it won't let you hurt the engine. And especially with your 4.10s, you have even less to worry about. Hell, when the skip-shift enables, it goes into 4th at way less than 1,000 RPM! Most people disable that, as I'm sure yours is. I put an eliminator in my wiring harness, so I still see the light on and then shift to 4th if I want to. (Usually not!)

**98maro** · 03-23-2011, 08:11 PM

Originally Posted by Eganslp

@Demon that's not even funny!! lol I can't believe you even mentioned that word lololol Prius ?'s a Pri-us anyway........j/k!!! no I don't really care about the gas mileage I just figured if I can drive it right then that will help enough with saving gas right there. that's all I need. plus I was more worried bout the engine lugging or struggling to pull it's own weight If I put it in to that low of a rpm.

@ 98maro go with the 4.11's or 4.10's w/e it maybe you def. won't regret it. I love it!!! It pulls likes ravaged ape in heat with a jetpack on!!!! (lol) My quater mile was a 12.7 @ 113mph & i can't launch my car for shit, trust me!!! I got a 2.20 60footer. Plus this is my DD & I drive 24 miles to work and then back. It's a mixture between city/highway I get on average 190miles to a tank or filling up every 4-5 days and that's with me playing around light to light sometimes. I can't help it... it's an SS!! But If you can leave alil earlier and cruz. Then your golden dude. 4.10's/4.11s w/e it is, is the way to go im telling ya man. Im not tryna start anything by saying this, but I beat other SS all the time by a couple of lengths!!! LoL I tell them I just have Exhaust..... I just fail to mention that i have gears!! lolol but shh that's my lil secret hah!! Hey, if they don't ask I don't tell.

lol im sure the guy was wondering why u smoke him if it was the same car lol..
im still confused on goin higher on gears, my gas mileage is not to bad..
at 70mpm on 6th gear rpms are around 1600 how its gonna be with 4'10s?

will you go back to stock gears?

**Eganslp** · 03-23-2011, 09:38 PM

@TooFast same here I put the eliminator harness in too.

Originally Posted by 98maro

lol im sure the guy was wondering why u smoke him if it was the same car lol..
im still confused on goin higher on gears, my gas mileage is not to bad..
at 70mpm on 6th gear rpms are around 1600 how its gonna be with 4'10s?

will you go back to stock gears?

hey Maro,
to honest I'm not sure what my RPMs are. I'll have to check for you when I'm on my way home in the morning.

As for the gearing nah, I love it. I'll never go back to them. I personally think that this is a perfect gearing for our cars. Not just light to light either, but on the highway too. I could cruz at like 55-60, still get good gas mileage and when someone pulls up next to me. Say..... the '04Mach1 w/CAI/exh & tune!!! I can drop it to third and romp em!!! lol & I mean romp them!!! They almost always ask (after they catch up) If I'm spraying.

This one particular guy, on my way down to the shore for the day followed me (lol) until I hit one of those half way stops that they have in jersey. He wanted to check my car so I said go ahead!!! He thought that I had sprayed him n that he beats SS all the time!! I just did one these "LoL" & listen I this is what I had; me (225lb) brother (263lb) & friend laying across the back(190lb)he'll nvr get into the back of my car again bc of that btw lol, also my eibach lowering springs(all4), some tools, and an extra tire in the car while on street tires the (17x9.5 stockers)
I love my SS!!!!! I really do!!!
Now i just have to learn how to launch from a dig w/o spinning till 3rd gear lol & I'll be good. :-)

currents mods are headers/9" rear with4.11's/rebuilt tranny (stage2)/rebuilt&rebalanced DS/ MT-315's

**98maro** · 03-23-2011, 10:02 PM

Originally Posted by Eganslp

@TooFast same here I put the eliminator harness in too.

hey Maro,
to honest I'm not sure what my RPMs are. I'll have to check for you when I'm on my way home in the morning.

As for the gearing nah, I love it. I'll never go back to them. I personally think that this is a perfect gearing for our cars. Not just light to light either, but on the highway too. I could cruz at like 55-60, still get good gas mileage and when someone pulls up next to me. Say..... the '04Mach1 w/CAI/exh & tune!!! I can drop it to third and romp em!!! lol & I mean romp them!!! They almost always ask (after they catch up) If I'm spraying.

This one particular guy, on my way down to the shore for the day followed me (lol) until I hit one of those half way stops that they have in jersey. He wanted to check my car so I said go ahead!!! He thought that I had sprayed him n that he beats SS all the time!! I just did one these "LoL" & listen I this is what I had; me (225lb) brother (263lb) & friend laying across the back(190lb)he'll nvr get into the back of my car again bc of that btw lol, also my eibach lowering springs(all4), some tools, and an extra tire in the car while on street tires the (17x9.5 stockers)
I love my SS!!!!! I really do!!!
Now i just have to learn how to launch from a dig w/o spinning till 3rd gear lol & I'll be good. :-)

currents mods are headers/9" rear with4.11's/rebuilt tranny (stage2)/rebuilt&rebalanced DS/ MT-315's

i think i made up my midn and im goin for 4'10s haha.. friends of mine said they are not good on the highway but they have m5... mustangs,,

i never have no 1 in my back seat haha they talk shit but i dont want more weight on my car you never know whats down the road haha

**Eganslp** · 03-23-2011, 11:01 PM

Originally Posted by 98maro

i never have no 1 in my back seat haha they talk shit but i dont want more weight on my car you never know whats down the road haha

True!!! That's why they are out now. I'm trying to make a delete setup like how the corvettes are made where their back comes up to the seat. Either that or go with rearseatdelete's setup but it's expensive as shit like 195 for it

**Too Fast** · 03-24-2011, 02:29 AM

Originally Posted by 98maro

i think i made up my midn and im goin for 4'10s haha.. friends of mine said they are not good on the highway but they have m5... mustangs,,

i never have no 1 in my back seat haha they talk shit but i dont want more weight on my car you never know whats down the road haha

Yup I can think of only one person on this site who went back to the 3.42s. I'd like to get some 4.10s also, and you're right, with our .5 OD 6th gear, the 4.10s are more than manageble on the highway.

It's like driving with no OD and a 1:1 4th gear and rear gears of 2.05!

Hell, my '68 Le Mans drop top has 2.52 gearing, with a 2(!) speed transmission. It's like 2400 RPM at 70, so I believe the RPMs in the F-Bodies with the M6 & 4.10s is still only ~2000.

**oldmanZ28** · 03-24-2011, 04:59 AM

70mph with an M6 & 4.10s' should put you at about 1875 rpm.

**WICKEDLS1** · 03-24-2011, 05:47 AM

Originally Posted by TLS_Addict

I would test something with my GTO and based on the "instant" mileage I found that if you lugged the engine too far you got worse mileage in a higher gear. I cant remember but if I was clost to 1k rpms I would make sure and pick a lower gear to get up around 1500 rpms. And the mileage did say it was better that way.

i was messing with that on mine the other day and if your around 1k rpms in 6th at 40MPH you would only get maybe 10-11 because you have to push the peddal down harder to keep the speed up which in turn hurts your mpg's. well with that being said i dont give a shit about mpg's i didnt buy a v-8 sports car to drive it like a fucking prius

drive it like you stole it thats my motto

**TWOBUELLS** · 03-24-2011, 11:12 AM

Just enter your data to see what different gearing will do for ya.
http://xse.com/leres/ss/calculator.html

**TLS_Addict** · 03-24-2011, 12:54 PM

This one works well too.

http://www.richmondgear.com/101032.html

OP, with .5 OD and 25.5 tires you are only at about 1621 rpms @ 60 mph with the 4.10s.