» Site Navigation | | » Recent Threads | | | | | | 09-14-2012, 12:35 AM | #1 | Member Join Date: Feb 2006 Location: Montreal Posts: 63 | Need to save on GAS, 6 speed? Where I live in Montreal Quebec Gas is through the roof! The Ti is really bad on 5th gear revving at 4+ on the highway. I own a manual 5 speed and actually look for a sixth sometimes. I make a long daily commute. Anyone successfully modify their existing transmission to a 6 speed? Can the existing tranni be modded to 6 gears? Simply adjusting the differential would most likely make the low end really slow. I have read some threads on this but nothing substantial. Anyone? __________________ | | | 09-14-2012, 12:41 AM | #2 | Senior Member Join Date: May 2005 Location: PA Posts: 1,906 | Swapping the diff would probably be your easiest for ya. Never heard of anyone modding the tranny. You could get a euro 6 speed tranny but not sure if it would bolt right up...? __________________ | | | 09-14-2012, 12:50 AM | #3 | Senior Member Join Date: Apr 2007 Location: Elizabeth City, NC Posts: 3,877 | You can't modify the trans for 6 gears. A 6spd trans from a euro M3 or US E46 330i would probably be easiest but would probably cost around $2000 USD. Is that worth it for a few more mpg? My ti can get 34-35mpg when I'm driving all hwy with 3.73 gears and keeping it around 70mph. I'd imagine a 3.25 rear end would be a great compromise towards more efficiency without sacrificing too much performance. Also, ditch the giant heavy wheels. That alone made a HUGE difference for me, 3-4 more mpg, and much better handling, acceleration, and braking. __________________ ~Dave~ 98 328ti Morea Grun slicktop 11 128i space gray slicktop 13 JGC WK2 Deep Cherry Search | RealOEM | | | 09-14-2012, 01:43 AM | #4 | Senior Member Join Date: Apr 2008 Location: Bethlehem, PA Posts: 1,106 | yeah, my 17's took off like 3mpg and the handing - accelerating went to crap. i just love them so much more. haha.. might have to go back to my 15's and 16's soon. money is tight Last edited by hotmilk400; 09-14-2012 at 01:46 AM. | | | 09-15-2012, 07:36 AM | #5 | Senior Member Join Date: Apr 2008 Location: Austin Posts: 3,059 | I drive a lot of city miles, and my diff is 4.44. With 17" alloys, I was averaging 16mpg. Switched it back to 16's, and was getting 24mpg. I miss my 15" steelies which were getting me 26mpg in city. So ya, wheel size makes a big difference in all the categories spider mentioned. __________________ Come get a ti-shirt Quote: From the e30 M3, evolved the e36. They were "Keepin it Real" when they introduced the 318ti ClubSport in '95 and the 318ti Sports from '96 to '99. After that... well nothing else really matters. ~Jess | | | | 09-16-2012, 03:22 AM | #6 | Senior Member Join Date: Mar 2005 Location: Portland Or Posts: 2,666 | Tire diameter and width matter wheel size not so much. If you buy narrow tires mileage will go up, tires that have a diameter that keeps the stock gearing help as well. Wide sticky tires = less gas mileage.. Tires that use higher pressure tend to get better mileage as well. Dave __________________ Dave - PDX 1995 318ti - Active Black and Tan. 2005 330xi - Mtech 1 - 6spd - Orient Blue/Black | | | 09-17-2012, 02:05 AM | #7 | Member Join Date: Oct 2011 Location: Louisville Ky Posts: 60 | I got the stock 3.44? rear diff. And the next step down with out going to a medium case is like a 2.xx out of a diesel, say maybe a 316d. Need to compare six speed ratio with the stock gear box. | | | 09-17-2012, 03:10 AM | #8 | Senior Member Join Date: Apr 2007 Location: Elizabeth City, NC Posts: 3,877 | The six speed from the e46 is same ratios just adds a .85 6th gear. Not many options at all for taller small case ratios. Plenty of medium case ratios available. __________________ ~Dave~ 98 328ti Morea Grun slicktop 11 128i space gray slicktop 13 JGC WK2 Deep Cherry Search | RealOEM | | | 09-18-2012, 03:18 AM | #9 | Senior Member Join Date: Aug 2008 Location: Globally Posts: 1,162 | Quote: Originally Posted by spidertri The six speed from the e46 is same ratios just adds a .85 6th gear. Not many options at all for taller small case ratios. Plenty of medium case ratios available. | The bad is the M4X is not a torque monster so adding a 0.85 overdrive is just gonna bog that engine. It's designed for autobahn speeds where you are high enough into the hp curve to use it. Dump the heavy wheels. | | | 09-18-2012, 03:32 AM | #10 | Senior Member Join Date: Mar 2005 Location: Portland Or Posts: 2,666 | I get into peak mileage at about 3300 rpm.. Bad tie choices cost money... LOL BTDT.. Dave __________________ Dave - PDX 1995 318ti - Active Black and Tan. 2005 330xi - Mtech 1 - 6spd - Orient Blue/Black | | | 10-08-2012, 04:10 PM | #11 | Member Join Date: Oct 2011 Location: Louisville Ky Posts: 60 | Alright, E30 318's 5th gear is .80. 6 speeds are .85. You loose the close ratio but gain overdrive. Im looking to go down this road. I can keep the small case diff, and the 5 speed is lighter then the 6 speed. Perfect..? | | | 10-08-2012, 06:57 PM | #12 | Senior Member Join Date: May 2010 Location: Montreal Posts: 283 | Are you saying the e30 318 gears are longer then the e36? edit, speaking of the transmission, not the diff. Last edited by mtlblue; 10-09-2012 at 03:38 PM. | | | 10-09-2012, 06:33 AM | #13 | Senior Member Join Date: Mar 2005 Location: Portland Or Posts: 2,666 | No matter what gearing,,, it takes X amount of HP to move the car, My 6 spd in my 330Xi only buy a couple hundred RPM from 6 to 5.. Buy some narrow 17 inch Michelin's and put 45 lbs in them and you'll get more mileage back. The 6 spd is also a fairly close ratio IMHO splits the gears nicely, but the car has way more power than a TI... Cheers and keep us up on the result,,, Dave __________________ Dave - PDX 1995 318ti - Active Black and Tan. 2005 330xi - Mtech 1 - 6spd - Orient Blue/Black | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |