3.25 LSD for sale $200

[SHARKY5]

I have a 3.25 LSD for sale. The differential is currently on my 528e and the diff has 180k miles. The diff is in mint condition. I am going to a 2.93 lsd but I would like to have a buyer for the 3.25 lsd before I take it out since I have no where to store it. It will be sold with no fluid and an e30 diff cover (I need my current cover to install the 2.93 lsd since it came from e30 325es). I would like to sell it locally. I am in the San Gabriel Valley about 15 miles east of down town Los Angeles. let me know if you are interested.

[Kyle in NO]

Not sure why you are doing that, but the tradeoff in drivability is not worth the mileage benefit...many people find an increase in mileage with a 3.25 or 3.46 unit over the 2.93 simply because you are not lugging the engine as much and don't have to use as much throttle to get moving...the 2.7 engine isn't powerful enough to befit from being under-geared.

[SHARKY5]

Kyle,

Thanks for the advice. I failed to mention my e28 is a 1984 528e which means its not a super eta. The stock diff for the 1984 528e is an open 2.93. About a year ago I took out the 2.93 and installed the 3.25 lsd which I love but due to business I will be traveling to Arizona at least twice a month. I am just looking to bring down the RPM's to stock levels because when I drive to AZ I am usually doing 80-85 mph with ocasional blast to 100. I just want to spare my engine some wear and tear.

[Kyle in NO]

If that is the only reason, you will not see any real benefit by going with the 2.93 other than your fun factor disappearing...

528e cars with the factory installed 3.46 are no less long-lived than their 2.93 counterparts...

[briansmith]

Not sure why you are doing that, but the tradeoff in drivability is not worth the mileage benefit...many people find an increase in mileage with a 3.25 or 3.46 unit over the 2.93 simply because you are not lugging the engine as much and don't have to use as much throttle to get moving...the 2.7 engine isn't powerful enough to befit from being under-geared.

Kyle, are any of those many people on the board?
I'd like to hear from someone who increased their fuel economy with a 3.25 or 3.46 unit over a 2.93. Perhaps their application is similar to mine, and I'm about to fit a numerically lower ratio in search of better fuel economy. Opening the throttle all the way to reach the desired speed seems like the best way to optimize fuel economy, not the other way around. My car sees around 50% of its miles at 65 or more mi/h, over nearly level ground, and I think the lower engine speed in that condition will help fuel economy during that condition. Of course, my car has the 3.5 liter, which may offer substantially more torque than the 2.7 liter, which I've never driven.

Everything else I've read by others about changing a diff. ratio to a numerically higher than stock ratio has claimed that a poorer (but worthwhile) fuel economy is realized despite the greater enjoyment of acceleration and climbing torque.

[Kyle in NO]

Of course at a highway cruise on level ground you will see better mileage with a 2.93 versus a higher ratio, but how many of us drive under ideal conditions? Most driving is not at 60mph on level ground. Around town or accelerating up to freeway speed, you will benefit more from a more usable ratio...

FWIW, I saw no real difference between 3.25 and 3.46 ratios in my old 535is...I also swapped out the 2.93 in my old 528e auto for a 3.73 and we don't really see much of a difference around town...highway cruise is obviously not as good...

[briansmith]

Of course at a highway cruise on level ground you will see better mileage with a 2.93 versus a higher ratio, but how many of us drive under ideal conditions? Most driving is not at 60mph on level ground. Around town or accelerating up to freeway speed, you will benefit more from a more usable ratio...

FWIW, I saw no real difference between 3.25 and 3.46 ratios in my old 535is...I also swapped out the 2.93 in my old 528e auto for a 3.73 and we don't really see much of a difference around town...highway cruise is obviously not as good...

For me, an increase of 1mpg would be considered a worthwhile improvement. Color me nuts.

I'm not convinced, though, that accelerating to highway speeds with a numerically higher diff. ratio gives better FUEL ECONOMY than doing so with a numerically lower diff. ratio. I already know it's more fun and happens more quickly, but are you convinced that a more closed throttle plate during "normal" acceleration somehow produces more fuel economy?

[Kyle in NO]

Open throttle plate the same amount, quicker to desired speed = burn less fuel...

[briansmith]

Open throttle plate the same amount, quicker to desired speed = burn less fuel...

OK, first you said to the other poster, "don't have to use as much throttle to get moving," so I thought you meant you don't push the pedal as far to accelerate. I'm still not sure which way you mean.

Either way, I have a crazy ass notion that WOT for as little time as possible to get to cruising speed and then the bare minimum to maintain it, with cruising speed sensibly chosen to use the brakes as little as possible, is the best way to drive to maximize fuel economy. That's the way the hybrid dudes do it to duke it out with each other for max. numbers. If that's true, then I'm still unconvinced that the low number diff. = fuel economy loss in acceleration. So far, my OBC agrees by posting better averages with this asinine driving technique. Don't try this at home, but if you do, corroborate my lame story.




Anyway, someone buy this lsd, 'tis the season to make 2 roosts for 2 Ben Franklins.

[SHARKY5]

Amen.

I will give it a week then it's going on ebay.