Opinions on 3.08 gears
02-27-2012, 08:47 PM
#1
2nd Gear Member
Thread Starter
Join Date: Mar 2011
Location: California
Posts: 170
Opinions on 3.08 gears
Ok guys Im positive almost everyone of you guys will say Nooo, get 373's or 410s but I have really thought it thru. I never drag race, and rarely race anybody on the street, but I do TON of highway driving. This weekend I went to Vegas and got 25mpg driving about 75-85mph and it got me thinking, with the gears, tune, exhuast and UDP's, I wondered if I can push 26-27mpg and also have close to 300 engine HP?
I want my Mustang to be a fast highway driver, I would rather be able to cruise at higher speeds than to have something faster off the line. Now on to the the questions. Hopefully Cliffyk can answer these
Do any of you guys have 3.08 gears and how do they feel?
Will the gears give me better mpg if installed along with a SCT Tuner and steeda UDP's and 2.5" exhuast (x pipe)?
Will the 3.08 gears make my car alot slower on the street?
Also, in the near future I am going to have my heads ported and polished and having the TB/Plenum ported/polished and comp stage 1 cams. Im hoping these mods and the mods I listed above will give me close to 350 "engine" hp but in combination with all the mods, keep my mpg the same or better.
Thanks and any and all info would be appreciated.
I want my Mustang to be a fast highway driver, I would rather be able to cruise at higher speeds than to have something faster off the line. Now on to the the questions. Hopefully Cliffyk can answer these
Do any of you guys have 3.08 gears and how do they feel?
Will the gears give me better mpg if installed along with a SCT Tuner and steeda UDP's and 2.5" exhuast (x pipe)?
Will the 3.08 gears make my car alot slower on the street?
Also, in the near future I am going to have my heads ported and polished and having the TB/Plenum ported/polished and comp stage 1 cams. Im hoping these mods and the mods I listed above will give me close to 350 "engine" hp but in combination with all the mods, keep my mpg the same or better.
Thanks and any and all info would be appreciated.
Last edited by supermario; 02-27-2012 at 09:25 PM.
02-27-2012, 09:01 PM
#3
4th Gear Member
Join Date: Jun 2010
Location: TEXAS
Posts: 1,452
since going up in the gears would make you lose a bit of mileage what you are saying should help you with your goal. And it may be a bit slower off the line but you are not really concerned with that so that shouldnt be a problem but you may have to add cams to your list to reach your power goal.
Heads up I completely understand what you are saying but more than likely ppl are gonna chime in and say "get a prius" and what not if you're concerned with mieage. But good luck in your project hopefully you gather the info you need.
Heads up I completely understand what you are saying but more than likely ppl are gonna chime in and say "get a prius" and what not if you're concerned with mieage. But good luck in your project hopefully you gather the info you need.
02-27-2012, 09:24 PM
#5
2nd Gear Member
Thread Starter
Join Date: Mar 2011
Location: California
Posts: 170
Yes I have plans on installing some comp stage 1 cams also. I forgot to put that into my mods. And I understand if you drive a Mustang you shouldnt worry about gas mpg's BUT I was very impressed with my mustang getting 25mpg just being stock. Anyhow, if I could reach 350hp (engine) and keep the mpg to 25mpg highway, I would be very happy. Gas prices are high in California but I dont want to drive a Prius either. I just want a nice fast highway car that doesnt break the bank. It cost me $95 Roundrtip toVegas. I didnt think that was too bad at all. I know some people that get that mpg with 6cyl.
since going up in the gears would make you lose a bit of mileage what you are saying should help you with your goal. And it may be a bit slower off the line but you are not really concerned with that so that shouldnt be a problem but you may have to add cams to your list to reach your power goal.
Heads up I completely understand what you are saying but more than likely ppl are gonna chime in and say "get a prius" and what not if you're concerned with mieage. But good luck in your project hopefully you gather the info you need.
Heads up I completely understand what you are saying but more than likely ppl are gonna chime in and say "get a prius" and what not if you're concerned with mieage. But good luck in your project hopefully you gather the info you need.
Last edited by supermario; 02-27-2012 at 09:31 PM.
02-27-2012, 09:31 PM
#6
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
You will get very slightly better highway fuel economy with 3.08:1 gears--however so slight that it would take 5 to 7 years to pay for the gears and the installation.
Ford's engineers picked the 3.27:1 gear for the new-edge Mustangs based on every consideration and compromise you can imagine--including especially fuel economy, as the CAFE (Corporate Average Fuel Economy) number would be greatly impacted by what they chose for as popular a model as the GT--guaranty it was a "best of both worlds" decision.
So my vote is, to meet your stated goals, stick with the stock gears.
Beyond that, here in the flatlands of Florida, if I had it to do over I would have stayed with the stock gears.
I installed 3.73s before I woke the engine up and now find that if I REALLY want to GO I can launch quite nicely (OK. a bit of clutch abuse) in 2nd gear--1st is useless other than to be nice to the clutch or when starting out on what would be defined as a "steep hill" down here.
What I really want now is a 3650 (I was told one could be built) or TKO 600 with the 2.87:1 1st gear. The "Viper spec" T-56 has a 2.66:1 1st but I really don't want a 6-speed...
Ford's engineers picked the 3.27:1 gear for the new-edge Mustangs based on every consideration and compromise you can imagine--including especially fuel economy, as the CAFE (Corporate Average Fuel Economy) number would be greatly impacted by what they chose for as popular a model as the GT--guaranty it was a "best of both worlds" decision.
So my vote is, to meet your stated goals, stick with the stock gears.
Beyond that, here in the flatlands of Florida, if I had it to do over I would have stayed with the stock gears.
I installed 3.73s before I woke the engine up and now find that if I REALLY want to GO I can launch quite nicely (OK. a bit of clutch abuse) in 2nd gear--1st is useless other than to be nice to the clutch or when starting out on what would be defined as a "steep hill" down here.
What I really want now is a 3650 (I was told one could be built) or TKO 600 with the 2.87:1 1st gear. The "Viper spec" T-56 has a 2.66:1 1st but I really don't want a 6-speed...
Last edited by cliffyk; 02-27-2012 at 09:38 PM.
02-27-2012, 09:38 PM
#8
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
Yeah, I though that might stir up some discussion...
Seriously though, I can devastate a bunch of higher powered cars "one the boulevard light-to-light course", by launching in 2nd. They get me for the first 75 to 100 feet, but then they have to shift and I am going 35 with 2500 rpm of powerband left...
Seriously though, I can devastate a bunch of higher powered cars "one the boulevard light-to-light course", by launching in 2nd. They get me for the first 75 to 100 feet, but then they have to shift and I am going 35 with 2500 rpm of powerband left...
Last edited by cliffyk; 02-27-2012 at 09:45 PM.
02-27-2012, 10:09 PM
#9
2nd Gear Member
Thread Starter
Join Date: Mar 2011
Location: California
Posts: 170
Thankyou, so I will keep the stock gears. Now, what would you opinion be on the rest of my mods and mpg's. I will be doing the ported/polish heads and TB/plenum, stage 1 cams, SCT Tuner, UDP's, and the exhuast that you reccomend, being 2.5" with X from manifolds back.
Also, when you say 2.5" exhaust, does that mean I can just go to the 2.5 piping and keep my stock mufflers and cats or do the mufflers and cats need to be upgraded to accept a 2.5" piping? Im just curious if I can go to a good muffler shop and ask them to swap out my piping to the 2.5 and just make their own X pipe and keep everything else stock? Or do i need to get hi-flow cats to make use of the increased diameter of the pipes? Im trying to keep the exhuast sound as quiet as possible. I know I doing the total opposite of everybody else but thats what I like. Quiet and decently fast on highways.
Few more Q's
1. Will polishing/porting heads increase or decrease mpg? (not that it matters because i want it done no matter what). Im assuming that will make the heads flow more efficient but also opens up the head and increases gas/air flow correct?
2. Will cams affect gas mpg alot or stay same if everything is matched up and tuned properly?
Thanks for your help and knowledge.
Also, when you say 2.5" exhaust, does that mean I can just go to the 2.5 piping and keep my stock mufflers and cats or do the mufflers and cats need to be upgraded to accept a 2.5" piping? Im just curious if I can go to a good muffler shop and ask them to swap out my piping to the 2.5 and just make their own X pipe and keep everything else stock? Or do i need to get hi-flow cats to make use of the increased diameter of the pipes? Im trying to keep the exhuast sound as quiet as possible. I know I doing the total opposite of everybody else but thats what I like. Quiet and decently fast on highways.
Few more Q's
1. Will polishing/porting heads increase or decrease mpg? (not that it matters because i want it done no matter what). Im assuming that will make the heads flow more efficient but also opens up the head and increases gas/air flow correct?
2. Will cams affect gas mpg alot or stay same if everything is matched up and tuned properly?
Thanks for your help and knowledge.
You will get very slightly better highway fuel economy with 3.08:1 gears--however so slight that it would take 5 to 7 years to pay for the gears and the installation.
Ford's engineers picked the 3.27:1 gear for the new-edge Mustangs based on every consideration and compromise you can imagine--including especially fuel economy, as the CAFE (Corporate Average Fuel Economy) number would be greatly impacted by what they chose for as popular a model as the GT--guaranty it was a "best of both worlds" decision.
So my vote is, to meet your stated goals, stick with the stock gears.
Beyond that, here in the flatlands of Florida, if I had it to do over I would have stayed with the stock gears.
I installed 3.73s before I woke the engine up and now find that if I REALLY want to GO I can launch quite nicely (OK. a bit of clutch abuse) in 2nd gear--1st is useless other than to be nice to the clutch or when starting out on what would be defined as a "steep hill" down here.
What I really want now is a 3650 (I was told one could be built) or TKO 600 with the 2.87:1 1st gear. The "Viper spec" T-56 has a 2.66:1 1st but I really don't want a 6-speed...
Ford's engineers picked the 3.27:1 gear for the new-edge Mustangs based on every consideration and compromise you can imagine--including especially fuel economy, as the CAFE (Corporate Average Fuel Economy) number would be greatly impacted by what they chose for as popular a model as the GT--guaranty it was a "best of both worlds" decision.
So my vote is, to meet your stated goals, stick with the stock gears.
Beyond that, here in the flatlands of Florida, if I had it to do over I would have stayed with the stock gears.
I installed 3.73s before I woke the engine up and now find that if I REALLY want to GO I can launch quite nicely (OK. a bit of clutch abuse) in 2nd gear--1st is useless other than to be nice to the clutch or when starting out on what would be defined as a "steep hill" down here.
What I really want now is a 3650 (I was told one could be built) or TKO 600 with the 2.87:1 1st gear. The "Viper spec" T-56 has a 2.66:1 1st but I really don't want a 6-speed...
02-27-2012, 10:30 PM
#10
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
You seem to be fixated on optimal fuel economy (an alien concept to me), and I assume fuel costs?
What this means basically is that you need to get an 87 octane optimised tune--then stop.
While the stock exhaust is a bit restrictive at higher rpms, from what you describe as your goals (optimal mpg) that is irrelevant as it has no impact on cruising and non "pedal-to-the-metal" operation. The stock tune however can be awakened by changes to the Spark Borderline table, which from the factory is very conservative.
"Cams" will hurt lower rpm fuel economy--a bunch, unless you wish to "downgrade" their specs. Again Ford's engineers selected cams based on the performance/CAFE curve. To go more radical will devastate low rpm fuel economy.
While performance tuning does, and is intended to, increase engine efficiency (that's where the added power come from); most performance mods through mpg to the wind in search of pumping up some portion (or all of) the powerband.
If MPG is your primary, or even secondary, goal then leave things pretty much stock other than as described above. I got 21,5 mpg in what used to be my "normal" commute (35 miles each way. 25 miles on I-95) with my current mods and tune, and 93 octane fuel. I could have by not changing to 3.73 gears, and with a more laid back tune (87), pumped that up to 23.5 or even 24.0.
But that was not my goal. When $10.25 a week difference in gas costs matters it's time to buy a Corolla...
What this means basically is that you need to get an 87 octane optimised tune--then stop.
While the stock exhaust is a bit restrictive at higher rpms, from what you describe as your goals (optimal mpg) that is irrelevant as it has no impact on cruising and non "pedal-to-the-metal" operation. The stock tune however can be awakened by changes to the Spark Borderline table, which from the factory is very conservative.
"Cams" will hurt lower rpm fuel economy--a bunch, unless you wish to "downgrade" their specs. Again Ford's engineers selected cams based on the performance/CAFE curve. To go more radical will devastate low rpm fuel economy.
While performance tuning does, and is intended to, increase engine efficiency (that's where the added power come from); most performance mods through mpg to the wind in search of pumping up some portion (or all of) the powerband.
If MPG is your primary, or even secondary, goal then leave things pretty much stock other than as described above. I got 21,5 mpg in what used to be my "normal" commute (35 miles each way. 25 miles on I-95) with my current mods and tune, and 93 octane fuel. I could have by not changing to 3.73 gears, and with a more laid back tune (87), pumped that up to 23.5 or even 24.0.
But that was not my goal. When $10.25 a week difference in gas costs matters it's time to buy a Corolla...