Gears vs. Mileage

[bodabdan]

Any input on your experience with mileage after changing rear gear ratios? I really need to be able to run some open highway and don't want to kill mileage.

[Curless]

Went to 4.10's lost 1 mpg...I WILL NEVER GO BACK!~

[ctrlraven]

Changing to 4.10 gears from stock 3.55 gears, most have seen a 1-2 mpg decrease. The performance increase which a tune will be required to benefit from the gears and alter the shift parameters is well worth it.

[kcmm]

when i bought my car it had 4.10's and no tune so as terry bradshaw would say my milage shot up faster than a bee stung stallion. since ive gotten a tune for 4.10's and the odometer tumble has decreased dramatically. dont know how milage was before though.

[MOTOWN]

I lost a 1mpg, maybe 2, opinions will vary Best gear swap i ever did!

[fastblackmerc]

You'll lose 1 to 2 mpg...... That's a given. The performance gained with the new gears and tune, yes you will need a tune, will put a smile on your face everytime you drive your MM.

[FastMerc]

My 2 cents I put the 4:10s in and love them. Then I had a stroker motor built and my Miliage is higher than stock Marauders and its awesome on the highway.

[bodabdan]

I don't know.... I appreciate the seat of the pants factor, no doubt about that. I will be using this car for business travel (and I travel a lot).
Anyone use a 3.73 ratio?

[1 Bad Merc]

I don't know.... I appreciate the seat of the pants factor, no doubt about that. I will be using this car for business travel (and I travel a lot).
Anyone use a 3.73 ratio?

Dont waste your time or money-I would either stay with the 3.55 if you are that concerned with mileage or swap to the 4.10's. What you dont realize is the tune in our cars was very conservative and had a lot of shifting schedule problems because they were detuning them.

Get a tune regardless which gears you have and you will be really surprised how nice your car runs and shifts. Tune and gears (4.10's) are probably the best thing you can do for your car- you will be shocked and pleased at the difference. If you want gas mileage you could always switch to a Fiesta!!!!

[RF Overlord]

The difference between the stock 3.55 and 4.10 is 15%. Going to 3.73 is only a 5% difference and isn't considered to be worth the cost, unless you can do all the work yourself.

[Pat]

What ^^^^they say. I also have a 3500 RPM stall converter. At 70 MPH with A/C on, triple digit temps and cruise control on I still am getting 22-23 MPG. I'm supercharged too, that really helped.

[bodabdan]

If you want gas mileage you could always switch to a Fiesta!!!!

No need for all that now......I don't want to have to get ugly in my first few posts...
I've had a 600 rwhp car before and that's not what I want this to be (it got 25 mpg by the way).
I will not accept that only a front wheel drive POS can get decent mileage, I know better. I'm not concerned about doing the work, I have three roll cabinets and a fully stocked service body on my F-350.
I'm only trying to do some due diligence and use the experiences of others figure out all the right combinations to get the results I'm looking for. I appreciate all the constructive input.

[RubberCtyRauder]

I would keep the 3.55 gear for now but get the sct tune from Mo's speed shop , a well involved vendor and member here. They can provide tune with different octane as well as both gear ratios. The tune will add 20 or so hp and revise the shift schedule from poor factory to much enjoyable. Then after you have run that and decide you want 4.10 , you can switch and already have a tune ready to download. This can all be done with a phone call and ups. Once received you plug the sct unit in the obdii port and download. The sct then remembers the factory tune to reload if needed

[chief455]

I would keep the 3.55 gear for now but get the sct tune from Mo's speed shop , a well involved vendor and member here. They can provide tune with different octane as well as both gear ratios. The tune will add 20 or so hp and revise the shift schedule from poor factory to much enjoyable. Then after you have run that and decide you want 4.10 , you can switch and already have a tune ready to download. This can all be done with a phone call and ups. Once received you plug the sct unit in the obdii port and download. The sct then remembers the factory tune to reload if needed
I fully agree with this advice. My car had 4.10 when I bought it, but the tune I purchased, 3.55 and 4.10 ratios included, improved everything. Start there, if 3.55 isn't enough pull, the 4.10 swap will cost you 1-2mpg as stated. But will add major fun factor :burnout:

[babbage]

I don't know.... I appreciate the seat of the pants factor, no doubt about that. I will be using this car for business travel (and I travel a lot).
Anyone use a 3.73 ratio?

I have 3.73 and am quicker and faster than most 4.10 N/A MM's.

Since everyone now Crusies at 80 mph now on the highway - with 3.73 you are right at 2500rpm. Past 2500 the gasoline goes fast.

4.10 @ 80mph = 2800-2900 rpm. Deal breaker for me. That and you might need a better drive shaft if you go 90-100 sometimes with 4.10's

If you want to accelerate quickly a high stall torque works well as it can slip when you floor it but locks up on the highway.

[bodabdan]

I have 3.73 and am quicker and faster than most 4.10 N/A MM's.

Since everyone now Crusies at 80 mph now on the highway - with 3.73 you are right at 2500rpm. Past 2500 the gasoline goes fast.

4.10 @ 80mph = 2800-2900 rpm. Deal breaker for me. That and you might need a better drive shaft if you go 90-100 sometimes with 4.10's

If you want to accelerate quickly a high stall torque works well as it can slip when you floor it but locks up on the highway.

Thank you Babbage! Great info!

[guspech750]

Any input on your experience with mileage after changing rear gear ratios? I really need to be able to run some open highway and don't want to kill mileage.

It is more about the SMILES per miles.

That is all that matters. :burnout:

Love my gears. Best mod ever. Even when I daily drove it. The way I pounded it. I did not and still do not care about the MPG's.

It's all about the SPG ;)


Sent from The White House on taxpayers dimes.

DTR + 4.10's + Eaton swap = Wreeeeeeeeeeeeeeedom

[chief455]

I have 3.73 and am quicker and faster than most 4.10 N/A MM's.

Since everyone now Crusies at 80 mph now on the highway - with 3.73 you are right at 2500rpm. Past 2500 the gasoline goes fast.

4.10 @ 80mph = 2800-2900 rpm. Deal breaker for me. That and you might need a better drive shaft if you go 90-100 sometimes with 4.10's

If you want to accelerate quickly a high stall torque works well as it can slip when you floor it but locks up on the highway.
he gets good mpg also ^^^
I spend more time cruising 65-70, so 4.10 = fun. good points to both - owner preference;)

[1 Bad Merc]

[QUOTE=bodabdan;1360875]No need for all that now......I don't want to have to get ugly in my first few posts...

I can fix phat but I cant fix ugly :)

[92BlackGT]

with 4.10's and Lidio tune, I got a best of 25.2 mpg from Heber, AZ to Santa Rosa, NM at 75 mph... i probably had a tail wind and a majority of that stretch was going down hill from the continental divide.
Typical is 23 mpg's going 70+ mph
mixed driving around 17 mpg's

[bodabdan]

I travel between locations in south Texas, Mississippi, Louisiana, Florida, Arkansas, and Alabama. The stretch in Texas is mostly 75 mph, but 75 will get you run over. 80-85 steady cruising is my goal, and doing it in comfort and style is important.

Thanks for the input.

[Vortech347]

I really didn't loose anything. I get pretty much whats on the window sticker. 18 city 23 highway.

[sflrainmaker01]

I travel between locations in south Texas, Mississippi, Louisiana, Florida, Arkansas, and Alabama. The stretch in Texas is mostly 75 mph, but 75 will get you run over. 80-85 steady cruising is my goal, and doing it in comfort and style is important.

Thanks for the input.

If you are going to be on the highway mostly doing 80+, then, IMO, the 4.10's might be a little much. I don't do a lot of highway driving, so the gears don't bother me. When I am on the highway, I keep it under 75mph and the gas mileage is pretty much what everyone else has said. I just wouldn't like the engine running 2800+ rpm for long trips.

Like 1 Bad Merc said, stay with the 3.55's and see how you like it. If you need some more SOTP thrill, then look at a gear swap. I don't think going up 1 gear size would make a huge difference. Maybe a 3.90 gear swap would be a good compromise?

[gdsqdcr]

I lost almost 2-3mpg in my commute. In my 04, stock gears, averaged 18-19mpg. In my 03, with 4.10's, I a stage around 16. Straight highway I only get a out 21 at 72-75mph. I do drive with California gas .... Which I know means I get less per gallon than anywhere else in this country.

The 4.10's are phenomenal. I like the off the line get up and go.

[Mac-MerC]

@bodabdan
Just do the damn gear swap.
You WONT regret it, makes it feel like the car just woke up from hibernation. If the swap wasnt worth it there would not be so many ppl telling u to do it..... DO YOU TRUST US?......

[Baaad GN]

1 Bad merc is ugly, 1 Bad merc is ugly, the horrors out there!!!!!!!

[lifespeed]

Keep the 3.55s for highway and install long tube headers with a SW exhaust and a tune for that SOTP Improvement while improving economy, power and engine life.

[1 Bad Merc]

1 Bad merc is ugly, 1 Bad merc is ugly, the horrors out there!!!!!!!

Ha Ha Ha !!!!!!!!!! :beer:

[Vortech347]

FYI I did a high speed cruise at 90mph for a few hours 2 years ago through the Nevada/Utah deserts and nailed 23mpg on the dot. Its around 3000rpm.

While RPM has a factor in MPG, LOAD has a more significant factor.

These cars have HUGE tires and soak up 4.10's. I had 3.73's once and felt like they weren't enough gear. So next car I did 4.10's. If my Marauder was my gofast/toy car It would have 4.30's without a doubt. We had 4.30's in our 01' Cobra (shorter tires too) and my wife daily drove that for 3 years. Before the E10 fuel came out that car would get around 26mpg highway even buzzing along at 3k @ 75.

I don't get how people say they LOST MPG in the city? I picked up a ton going to 4.10's. Are you guys driving at 2000+RPM with OD locked out?

[fastblackmerc]

I don't think there is one person who regretted installing 4.10's.

Your RPM's will increase by about 200 when you are at cruising speed. The extra RPM's will not affect the wear in the engine.

You will not need a new drive shaft with the 4.10's unless you do sustained speeds at 120+.

You will lose 1-2 MPG.

The Marauder was designed to run 4.10's but had to go with 3.55's the help meet CAFE.

JUST DO IT!!!

[sflrainmaker01]

The Marauder was designed to run 4.10's but had to go with 3.55's the help meet CAFE.

JUST DO IT!!!

It also should have been designed/equipped with the Eaton! :burnout::burnout:

[fastblackmerc]

It also should have been designed/equipped with the Eaton! :burnout::burnout:

The Marauder was designed with 4.10's... that a fact. Not should have been...

[GODFATHER]

Not to be funny but will 4:10's in my 2v 2002 GMQ be worth it and will it need a tune.. What gear is in my 2002

[redmercy04]

How can u tell if u have 4.10s. Picked up my MM in Nov last year. In great shape came with flo-masters. Dont no if this will help but cruising bout 75 my rpm are at 2600

[MOTOWN]

How can u tell if u have 4.10s. Picked up my MM in Nov last year. In great shape came with flo-masters. Dont no if this will help but cruising bout 75 my rpm are at 2600

Turn the rear tire by hand one complete turn, if you have 4:10s the drive shaft will turn 4.1 times.

[Vortech347]

How can u tell if u have 4.10s. Picked up my MM in Nov last year. In great shape came with flo-masters. Dont no if this will help but cruising bout 75 my rpm are at 2600

That is right for 4.10's. You can either move the wheels and look the drive shaft or use a GPS and compare your mph and RPM using a gear calculator.

[justbob]

When I was automatic I got 19.8 w/4.30's driving very easy at 80 except for 2 or 3 WOT blasts. Don't recall the RPMS.


Self proclaimed Builder Of Badassery.

Buy it, Break it, Build it BETTER.
"Since 2004"

[RF Overlord]

Not to be funny but will 4:10's in my 2v 2002 GMQ be worth it and will it need a tune.. What gear is in my 2002Your GMQ has either 2.73 or 3.27...look on the door sticker for the axle code, or check the tag on the differential cover.

The 2V doesn't respond to higher gear ratios as well as the 4V...installing 4.10s in a stock GMQ is not ideal...3.73 is about as high as you should go and is equivalent to 4.10s in a Marauder, but I would only install 3.73s if most of your driving is around town. Also, your fuel economy will suck on the highway. 3.55 is considered the best all-around ratio for a CV or GM.

[71cyclone]

Your GMQ has either 2.73 or 3.27...look on the door sticker for the axle code, or check the tag on the differential cover.

The 2V doesn't respond to higher gear ratios as well as the 4V...installing 4.10s in a stock GMQ is not ideal...3.73 is about as high as you should go and is equivalent to 4.10s in a Marauder, but I would only install 3.73s if most of your driving is around town. Also, your fuel economy will suck on the highway. 3.55 is considered the best all-around ratio for a CV or GM.

I had 3:73 's in my 03 v8 [p code 2v eight ] mountaineer /the wagon was quick and it delivered 15 city and 18 Hi way ; it later had transfer case issues and was sold .138;000 miles ,it will be missed [marauder pipes included ] correction [ magna flo marauder knock off pipes ]

[HotRaud90]

Alright, new guy here. Seriously looking into a MM with 62k miles for around 11.5k. It's had a few things done to it. When current owner bought from previous owner, it had 4.10 gears in it. Current owner is an older guy that didn't want off the line kick, so he had 3.23 gears installed instead of stock 3.55 :(
He also said that the speedo is off which means it was never tuned for 3.23s. It also has 255 rear tires which further messes with odometer readings (I think?).

Well, he said he would give me the 4.10 gears with the purchase, and another positive is that he said he had the axles replaced during the swap. Now I'm just stuck wondering if I should go find/trade for 3.55s, install and get a lidio tune OR just use the 4.10s I have, install them and get the lidio tune for that ratio. I KNOW I KNOW, most of you will tell me to go with 4.10 and never look back ;)
But, I'm lookin for better fuel economy and since I will be puttin the good juice in it (89-93), I need to make sure I'm makin the right choice with the greenbacks. I don't wanna drop the dime for one swap and then figure out it wasn't the best choice.

This would be a DD with a 60 mile round trip commute, highway 65%/city 35%. I have no problem with being a lightweight on the pedal. I usually go 65 on the highway and around 40-50 in city driving.

I'm sorry for the long winded post. Any/all help is appreciated. This would be so much easier if it had the stock 3.55s in it :(

[camelgrundle]

Lol if I had a nickel for every time some one asked this question over the years. It's a marauder make it fast ! 410s are a blast on the highway especially with a centri.

[chief455]

Alright, new guy here. Seriously looking into a MM with 62k miles for around 11.5k. It's had a few things done to it. When current owner bought from previous owner, it had 4.10 gears in it. Current owner is an older guy that didn't want off the line kick, so he had 3.23 gears installed instead of stock 3.55 :(
He also said that the speedo is off which means it was never tuned for 3.23s. It also has 255 rear tires which further messes with odometer readings (I think?).

Well, he said he would give me the 4.10 gears with the purchase, and another positive is that he said he had the axles replaced during the swap. Now I'm just stuck wondering if I should go find/trade for 3.55s, install and get a lidio tune OR just use the 4.10s I have, install them and get the lidio tune for that ratio. I KNOW I KNOW, most of you will tell me to go with 4.10 and never look back ;)
But, I'm lookin for better fuel economy and since I will be puttin the good juice in it (89-93), I need to make sure I'm makin the right choice with the greenbacks. I don't wanna drop the dime for one swap and then figure out it wasn't the best choice.

This would be a DD with a 60 mile round trip commute, highway 65%/city 35%. I have no problem with being a lightweight on the pedal. I usually go 65 on the highway and around 40-50 in city driving.

I'm sorry for the long winded post. Any/all help is appreciated. This would be so much easier if it had the stock 3.55s in it :(
the difference in economy from tuned 3.55 to tuned 4.10 is minimal. The fun factor however is substantial.
Install the free gears, tune for them, enjoy.

[HotRaud90]

Lol if I had a nickel for every time some one asked this question over the years. It's a marauder make it fast ! 410s are a blast on the highway especially with a centri.

I know, I know lol. I almost hated asking for the amount of noob flames I would receive :rolleyes:

I'm pretty sure I could get around 23 highway with a lidio tune and the way I drive. Just mostly wondering about the city part. Of course there's always the burning desire to mash the pedal at the dig, but I drive pretty conservatively to keep the green in my pocket.

Can anyone attest to gettin around 17 city with 4.10s, a tune, and a light foot? 19-20 mpg combined would be enough for me to go ahead and do the 4.10s.

[pantheroc]

3.55 is considered the best all-around ratio for a CV or GM.

Thanks Bob, I was just thinking of putting the 3.55's in the CV.

Would it throw an error if I don't get a tune? Car has traction control.

[fastblackmerc]

Thanks Bob, I was just thinking of putting the 3.55's in the CV.

Would it throw an error if I don't get a tune? Car has traction control.

No you will not get any "errors".

[RF Overlord]

so he had 3.23 gears installedNo, he didn't...there's no such ratio. Maybe he meant 3.27? Even that is only one step down from stock and would have not been worth the money he paid to have it done unless he drove an enormous number of highway miles.

If you're going to change it, go all the way to 4.10, unless YOU are planning to drive a huge amount on the highway, then do 3.73s...it will be a nice bump from your current but won't kill you on highway economy.

[gdsqdcr]

I know, I know lol. I almost hated asking for the amount of noob flames I would receive :rolleyes:

I'm pretty sure I could get around 23 highway with a lidio tune and the way I drive. Just mostly wondering about the city part. Of course there's always the burning desire to mash the pedal at the dig, but I drive pretty conservatively to keep the green in my pocket.

Can anyone attest to gettin around 17 city with 4.10s, a tune, and a light foot? 19-20 mpg combined would be enough for me to go ahead and do the 4.10s.

80 mile commute every day. Mix of highway and city in some of the worst traffic known to man kind, the San Francisco Bay Area.

I average around 17 in commute and just below 20 on highways. O and sometimes ... I .... umm ... the tires loose traction upon acceleration on an on ramp.

Anthony

[IwantmyMMnow!]

Can anyone attest to gettin around 17 city with 4.10s, a tune, and a light foot? 19-20 mpg combined would be enough for me to go ahead and do the 4.10s.

I've had my 4.10s and a tune for almost 2 years now. I wouldn't say that I'm a 'light foot', but I don't mash on it every day, either...just every other day. I get around 17mpg driving around town and around 21mpg on the interstate as long as I keep it below 77mph/2500 RPMs...I once got 23mpg, but kept it under 70mph the entire way, which was meh...

The MPG I get now are about 1-2mpg lower than what I was averaging with the 3.55s. If you drive 12,000 miles a year, you will need to purchase about 4 more tanks of gas running 4.10s vs 3.55s during that span; if 91/93 octane is $4/gal, that's about $300 more a year, or $25 extra a month.

There are other things besides driving habits that can help maximize MPGs.

[L.Mark]

Warning!!! You will get noticeably less gas mileage. I usually drive the speed limit +/- 5-10mph...I just have a tune and can't stay out of the pedal. It is my fault for a heavy foot, but the smiles-to-miles factor is just too tempting. Heaven help me when the 4.10's are installed!!!

[RF Overlord]

Thanks Bob, I was just thinking of putting the 3.55's in the CV.

Would it throw an error if I don't get a tune? Car has traction control.No error, but your speedo will be off and depending on the year you may need a tune to correct it, or a friendly local tech with an IDS.

See you and Diane in Looseville?

[HotRaud90]

No, he didn't...there's no such ratio. Maybe he meant 3.27? Even that is only one step down from stock and would have not been worth the money he paid to have it done unless he drove an enormous number of highway miles.

If you're going to change it, go all the way to 4.10, unless YOU are planning to drive a huge amount on the highway, then do 3.73s...it will be a nice bump from your current but won't kill you on highway economy.

Um...unless I'm just completely inept, there IS such a thing as a 3.23 ratio. Used in plenty of cars. You are right in a sense though because (after some quick research) I don't believe they make a 3.23 for 8.8" rear end specs, which the Marauder has...hence why you're probably right that it's 3.27 in this case.


I've had my 4.10s and a tune for almost 2 years now. I wouldn't say that I'm a 'light foot', but I don't mash on it every day, either...just every other day. I get around 17mpg driving around town and around 21mpg on the interstate as long as I keep it below 77mph/2500 RPMs...I once got 23mpg, but kept it under 70mph the entire way, which was meh...

The MPG I get now are about 1-2mpg lower than what I was averaging with the 3.55s. If you drive 12,000 miles a year, you will need to purchase about 4 more tanks of gas running 4.10s vs 3.55s during that span; if 91/93 octane is $4/gal, that's about $300 more a year, or $25 extra a month.

There are other things besides driving habits that can help maximize MPGs.

Good to hear. Thanks for the info and everyone else who has/will contribute to answering my question.

[MMinWPB]

3.23 vs. 3.27..."probably right"..."right in a sense"...the 3.23 thing in this forum MUST have been nothing more than a few typos...probably...

[prchrman]

did not read all the posts but I put in 4.10s, CAI and Mo tune and went from 19.5 city to 19 city and 24.5 hiway to 22.5 hiway and lots and lots more bottom end. Tune and CAI seemed to help more than gears to me, but I could be wrong.

[RF Overlord]

Um...unless I'm just completely inept, there IS such a thing as a 3.23 ratio. Used in plenty of cars.OK, I didn't think I had to actually SAY that there's no such ratio for the Ford 8.8... :rolleyes:

[HotRaud90]

OK, I didn't think I had to actually SAY that there's no such ratio for the Ford 8.8... :rolleyes:

Hah! Fair enough. Just wanted to make absolutely sure. Sometimes (no insult or implication towards you), you just never know when it comes to the interweb and the people that peruse it :rolleyes: ...


did not read all the posts but I put in 4.10s, CAI and Mo tune and went from 19.5 city to 19 city and 24.5 hiway to 22.5 hiway and lots and lots more bottom end. Tune and CAI seemed to help more than gears to me, but I could be wrong.

Awesome. Thanks for the numbers. I appreciate all the info. Just a future owner soakin up as much as he can :D

[MyBlackBeasts]

Actual Personal Experience

Stock = 22 mpg:)
Change to 4.10s = 20.5 mpg:D
Install Trilogy = 24.5 mpg:D:burnout::D

Conclusion = install 4.10s and as soon as you can add Boost so you get better mpg than stock along with huge increase in "smiles per mile"! :D

(Then do conversion to manual 6-speed and get 33mpg!)

[Finally]

Has any one run a set of 3:90 gears in their MM,if I calculate it right rpm's should sit around 2200 at or near 70 mph

[RubberCtyRauder]

Has any one run a set of 3:90 gears in their MM,if I calculate it right rpm's should sit around 2200 at or near 70 mph


nevermind..thought there was no 3.90 rear gear for 8.8 inch..but motive gear has them

[fastblackmerc]

Has any one run a set of 3:90 gears in their MM,if I calculate it right rpm's should sit around 2200 at or near 70 mph

I doubt it.....

Just install the 4.10's and be done with it.

[Finally]

[QUOTE=fastblackmerc;1375380]I doubt it.....

Just install the 4.10's and be done with it.[/

I might not want to cruise at what is it 23 2400 rpm to me anyways at least a couple of hundred rpm makes a differance on the hwy which is why I asked if anyone has run them,I'm bad that way and tend not to follow everyone on what they do.
:beer: