what do 4:10's do to fuel mileage

[jay87lx]

Hi, I have been doing a lot of reading, maybe not enough, but I see many guys adding 4;10's out back. What does that drop your fuel mileage to and how do they run on the highway with such a gear?

[03Merc]

Hi, I have been doing a lot of reading, maybe not enough, but I see many guys adding 4;10's out back. What does that drop your fuel mileage to and how do they run on the highway with such a gear?


Highway speeds will increase the rpm's a few hundred burning more fuel on top end. You will lose some MPG (not much tho) but You will gain more SPG (SmilesPerGallon). Gets the car moving a lot better low end. I don't have them yet but they are My next mod for sure!


2004 MM Build #1618 & DTR #537

[RubberCtyRauder]

2500 rpm @ 70 mph. Lose about 2 mpg on hwy. around 21 mpg. I don't check my city driving and it's not a daily driver for me.

[martyo]

If you decide to go with a gear swap, I would be happy to help you out with the tune that you will need.

[jay87lx]

Thank you marty. I buy and sell cars and the guy I deal with (I use his license to go to the auction) has 3 right now, one has a recovered theft title with 72K so I have been thinking of getting it- It is clean underneath but needs some interior work

[rauder88]

4.10s will ruin your gas mileage!!!!
Trust me you will not be able to leave any stop lights signs without going WOT.

Seriously though, 4.10s basically no effect on cruising RPM mileage. Your miles per tank will go down as you will not be able to keep your food out of it lol

Do it, you will not be let disappointed, and go with MO's (martyo) for the tune!

[RubberCtyRauder]

Thank you marty. I buy and sell cars and the guy I deal with (I use his license to go to the auction) has 3 right now, one has a recovered theft title with 72K so I have been thinking of getting it- It is clean underneath but needs some interior work


What kind of interior work? Trim, seat covers, floor mats etc. are discontinued and hard to come by. There are various pieces being sold thru here (for sale section) and on ebay and even craigslist. Not saying it can't be fixed, just that it might take a little searching.

[RF Overlord]

While your highway MPGs will drop slightly, your around-town MPG may not see a hit at all as it will take less pedal to get the car moving. On the average, I lost about 1½ MPG.

[jay87lx]

What kind of interior work? Trim, seat covers, floor mats etc. are discontinued and hard to come by. There are various pieces being sold thru here (for sale section) and on ebay and even craigslist. Not saying it can't be fixed, just that it might take a little searching.
The armrest cover is ripped- easy fix at my upholstery shop, but the trim, like the trim piece that holds the power window buttons is all scratched, stuff like that, the gauge pod is missing, no radio, seats are good, Personally I would replace the carpet but that's just me.

[L.Mark]

I've been debating doing this since I bought the car, I have to replace the gears now so I just decided to upgrade...will be done in a couple weeks by Curless Auto!!! YeeeHawwww!!!

[345HP87SSAC]

My car dropped to 21 on way home from GA. From about 23 before the swap.

[martyo]

My car dropped to 21 on way home from GA. From about 23 before the swap.

Do you want us to switch it back?? :D

[fastblackmerc]

Your RPM's will be about 200 higher at 70MPH and you'll lose 1-2MPG.

You will get more "smiles to the miles"!

[ctrlraven]

RPMs can also vary depending on your rear tire size but not much.

Here is some effective rear gear ratio samples with using 4.10s and a different tire size than the factory 245/55-18 on the rear.
235/50-18 is 4.30
255/55-18 is 4.04
265/50-18 is 4.13

I waited years to install my 4.10s, even had bought the gears twice and turned around and sold them. Third time is the charm and wish I hadn't waited so long.

If you are worried about gas mileage then this is not the car for you, it's big and under powered (NA) for it's size. A tune and 4.10s will really wake the car up and it's how the car should of been from factory.

[fastblackmerc]

A tune and 4.10s will really wake the car up and it's how the car should of been from factory.

Per the "Father of the Marauder" 4.10's were originally spec'd for the car but the bean counters needed the extra mile or two for CAFE.

This is what CAFE is:
http://www.nhtsa.gov/fuel-economy

[tbone]

I saved my 3.55's but I know I will never use them again. Paperweights.

[fastblackmerc]

I saved my 3.55's but I know I will never use them again. Paperweights.

I have mine too... 15k miles on them.

[88CuttyClassic]

I waited years to install my 4.10s, even had bought the gears twice and turned around and sold them. Third time is the charm and wish I hadn't waited so long.


i hope i dont fall into that same trap. i have all the parts except axles (i'm going over to 31 spline). I've already thought about selling them to so i can fix my monte SS.

[345HP87SSAC]

Do you want us to switch it back?? Quote from MO-------------------

Let me think on that......Heck no it is peppy like 429 HP should be. Before it was a dog. Now it is spunky without having to beat on it. It is a very worth while mod!

[MOTOWN]

Not another are 4:10s a worthwhile mod thread! :shake:

[Finally]

Curious what the diff would be in rpm between 4:10 and 4:30.

[tbone]

I have mine too... 15k miles on them.

Mine are well over 100k and look brand new.

[tbone]

Not another are 4:10s a worthwhile mod thread! :shake:

New members ask old questions. The subject line is clearly stated. Don't open it if it annoys you. :run:

[fastblackmerc]

Curious what the diff would be in rpm between 4:10 and 4:30.

Who cares as long as it's quite and your going forward!

[Marauderman]

I saved my 3.55's but I know I will never use them again. Paperweights.


I have mine too... 15k miles on them.

FWIW---not to de-rail much--but I re-used my old 355's twice----so best to keep'um--you never know---

AS for 410's--believe its been answered already----the only way to go--not much more RPM and no one cares about anything else--cars always get gas when needed--to my knowledge that has never changed---carry on

[MOTOWN]

New members ask old questions. The subject line is clearly stated. Don't open it if it annoys you. :run:

Thats not the point! This has been discussed so many times , it has to be the easiest subject to search for , like whats the best oil , spark plugs to use!

I'll take your advice on your ongoing hood voyage! Lol

[Finally]

Thats not the point! This has been discussed so many times , it has to be the easiest subject to search for , like whats the best oil , spark plugs to use!

I'll take your advice on your ongoing hood voyage! Lol

Soooooooooooo what is the best oil to use. Lol

[88CuttyClassic]

common questions forum? sticky the best ones, move them there.

[martyo]

Which weight motor oil is best to use with a 4.10 gear?

[MOTOWN]

Which weight motor oil is best to use with a 4.10 gear?

Didn't you get the memo that comes free with a can of Maf/Iac cleaner?:rolleyes:

[tbone]

Thats not the point! This has been discussed so many times , it has to be the easiest subject to search for , like whats the best oil , spark plugs to use!

I'll take your advice on your ongoing hood voyage! Lol


So what? I'll bet you asked a bunch of questions that had already been answered when you first joined. What are you the thread police?

"Oh no, another guy complaining that a topic has already been covered and says to use the search function"! :bigcry::bigcry::bigcry:

My hood thread has 5000 hits. Make fun of it if you want........Let's see something you've done that's worth looking at dickhead.

[MOTOWN]

So what? I'll bet you asked a bunch of questions that had already been answered when you first joined.

"Oh no, another guy complaining that a topic has already been covered and says to use the search function"! :bigcry::bigcry::bigcry:

Man your crying more than a guy who's bondo keeps cracking! ........oh wait, never mind! :violin:

[tbone]

No that is you crying.

The bondo didn't crack again. It bubbled. At least I had the balls to try.

[solo5057]

man this is almost like Friday night fights!!! lol now have to keep looking

[MOTOWN]

Im just yanking Tbones chain! Lol nothing to see here keep it moving! Lol

[Marauderman]

reminds me of the days of 'Mo and TAF"--that was the best--here on your local MM.net channel---

[MERCULES]

:popcorn::popcorn::popcorn:

[MyBlackBeasts]

Hi, I have been doing a lot of reading, maybe not enough, but I see many guys adding 4;10's out back. What does that drop your fuel mileage to and how do they run on the highway with such a gear?


If you are concerned about fuel mileage, add boost to the 4.10s and gain 2mpg.

OEM w/3.55s = 22mpg
OEM w/4.10s = 20.5 mpg
Boost w/4.10s = 24mpg

[MrMarauder]

@Ctrlraven, I am buying new tires for the rear soon because the previous owner had a different size on each wheel. I am also doing the 4:10 gear change next month. I will only be able to afford one set of tires. You gave some examples of different sizes. If I could only buy one set, which size would you recommend for the rear? i will be doing a combo of city and highway driving and I'm not worried about MPG.

[ctrlraven]

@Ctrlraven, I am buying new tires for the rear soon because the previous owner had a different size on each wheel. I am also doing the 4:10 gear change next month. I will only be able to afford one set of tires. You gave some examples of different sizes. If I could only buy one set, which size would you recommend for the rear? i will be doing a combo of city and highway driving and I'm not worried about MPG.
Is your car an 03 or 04? Do you have a tune?

If it's an 03 without traction control then you could always go with the same size as in the front which will then allow you rotate tires. If it's a 04 then you'll have to run a larger size on the rear like the 255/55 or the 265/50. The 255/55 will fill up the wheel well a lot more and overall the rear will retain it's rake stance. The 265/50 is only 4% bigger diameter than the front and about .5% smaller than the factor 245/55. Nitto is the only brand that makes the tire which is a summer performance low tread rating (360 I think).

I would probably go with the 255/55, more of a common tire to find and beefy look.

[MrMarauder]

Mine is an 03 without traction control. Would I be better off keeping the tires all one size?

[ctrlraven]

Mine is an 03 without traction control. Would I be better off keeping the tires all one size?
If you don't care about the overall stance look of the car and want to rotate your tires then sure. You will need to correct the speedometer via the tune and need a 4.10 gear tune.

[Red Rum]

If you get it. And need the two auto meter gauges and the panel. I have a extra one. I can see you.

[jay87lx]

Thanks for the replis guys. I am certainly not worried about fuel mileage as i currently drive a 99 expedition with a 5.4. I have a highway drive to work everyday and was more just wondering what effect that gear would have on RPM. I didnt want to have the cars rpm's screaming on the highway but it sounds like the gear has very minimal draw backs

[Finally]

Thanks for the replis guys. I am certainly not worried about fuel mileage as i currently drive a 99 expedition with a 5.4. I have a highway drive to work everyday and was more just wondering what effect that gear would have on RPM. I didnt want to have the cars rpm's screaming on the highway but it sounds like the gear has very minimal draw backs

I had the same concerns and was being stubborn on the issue and even thought about going with 3:89 gears instead ,in the end I listened to everyone on this site and to the advice of Marty who has supplied me with the tune and have no regrets.
Just do it and make sure and hook up with Marty O on this site for your tune

Tony

[jay87lx]

I had the same concerns and was being stubborn on the issue and even thought about going with 3:89 gears instead ,in the end I listened to everyone on this site and to the advice of Marty who has supplied me with the tune and have no regrets.
Just do it and make sure and hook up with Marty O on this site for your tune

Tony
How much is said tune and do you have to take the car to him or is the tune programmed into a tuner and you just plug into the OBDII?- Just curious

[RubberCtyRauder]

Send MartyO a pm for a price, and yes, he can send it via email or download it to an sct device and send it if you need to purchase one. You need a SCT handhed to store the tune and to store the factory tune.

[MrMarauder]

If you don't care about the overall stance look of the car and want to rotate your tires then sure. You will need to correct the speedometer via the tune and need a 4.10 gear tune.

I like the stanced look better personally. Which tires would be best in that case. I'm definitely doing the 4:10 gears. What changes need to be made to the speedometer and it was mentioned about the two autometer gauges. Do those have to be adjusted too?

I just bought this Marauder last month to go with my 69' Marauder x100 and I'm keeping it forever. I wanted it way too long to let it go. I sold my 1995 M3 to buy this and I haven't regretted the decision at all. Now it's time to have some fun with it. My dream build is going to be dropping a supercharged 5.4L in my new beast or I could just piss off everyone and put an ecoboost from an f-150 in it for to give it a quick 365hp. All in due time!

[RubberCtyRauder]

A supercharged 5.4 swap isn't going to fit under the stock hood. You"ll be cutting a hole in it. Nobody has done a 5.4 swap in a Marauder as it is not practical, Better off doing an eaton swap as it is called here, there is a parts list under the power added section.

[jay87lx]

Send MartyO a pm for a price, and yes, he can send it via email or download it to an sct device and send it if you need to purchase one. You need a SCT handhed to store the tune and to store the factory tune.
When you talk about an SCT device is this what you are referring to?

http://www.sctflash.com/products.php?PID=74&VID=#2

I had something similar for my expedition, (Edge Evolution CTS) I liked it not so much for the tune or the ability to change shift points etc but rather the ability to select particular PIDS to keep an eye on. (ie, Trans temp, coolant temp, etc tec)

[martyo]

When you talk about an SCT device is this what you are referring to?

http://www.sctflash.com/products.php?PID=74&VID=#2

I had something similar for my expedition, (Edge Evolution CTS) I liked it not so much for the tune or the ability to change shift points etc but rather the ability to select particular PIDS to keep an eye on. (ie, Trans temp, coolant temp, etc tec)

Yes.

I sell a package with the device and the tune.