rpiereck Posted December 17, 2008 Share Posted December 17, 2008 I got a buddy at work who's an anti internet type () and he's got a mid 90s Legacy Wagon with automatic transmission. He's got the place in the fuse box where he can insert a fuse for FWD, and he's wondering if he can wire in a switch inside the cabin so he can have front wheel drive when he wants for economy instead of all wheel drive. I told him he'll still be dragging the whole rear wheel portion of the drive system and his fuel economy wouldn't be that much greater but he wants to do it anyway. If he wires in a switch will that damage his Legacy in any way? Is the FWD fuse to be used only in emergenies for a limited distance? I told him to read his manual, but of course he's lost it.... thanks! Link to comment Share on other sites More sharing options...
bratman18 Posted December 17, 2008 Share Posted December 17, 2008 Yes he could use a switch it wouldn't hurt a thing but you're right the fuel economy doesn't change at all! The all wheel drive system works so that as long as you are cruising down the road the rear transfer clutches are actually disengaged. So most of the time you are in front wheel drive anyway. The system kicks in when the front wheels spin or when you stomp on it but rolling along it's in two wheel drive. But yes it can be done. Hope this helps! Link to comment Share on other sites More sharing options...
Snowman Posted December 17, 2008 Share Posted December 17, 2008 Using a switch instead of a fuse won't cause any harm to the car. The FWD fuse provides constant full power to the duty C solenoid, disengaging the clutch that connects the rear wheels to the transmission. You can operate indefinitely like this without any ill effects. I know people who run with the FWD fuse in to improve fuel economy, and I drove about 3000 miles with it in last fall (long story). As to actual improvement in economy, theoretically it should increase, but it's hard to say how much. Yes, you are still dragging all the RWD stuff along and causing drag that way, so it wouldn't be as good as having a solely FWD car. However, the load on the entire drivetrain and therefore drag is reduced. Even when the clutch pack is barely engaged, as it is when you're just driving along normally (no slippage detected), the tiny differences in tire rotations caused by slight variations in size or when turning cause the drivetrain to load up and cause more drag. Additionally, by reducing this load, the drivetrain has less stress on it and will last longer. I really can't say how much my economy improved as a direct result of operating in FWD. I got better mileage at the time, but I was also driving on better roads, along with a variety of other factors that usually help mileage. Link to comment Share on other sites More sharing options...
rpiereck Posted December 17, 2008 Author Share Posted December 17, 2008 I think it's a case of switch jealousy... I recently bought my 91 Loyale and it has the FWD switch on the gearshift, and he really liked that idea. He wants to be able to switch in and out like me, I guess. I don't know if the system on the Loyale works similar to the one on the Legacy. I actually didn't think the switch would hurt the transmission, but I told him I'd check anyways. I bet he'll be happy and switched in by weekend's end. Thanks! Link to comment Share on other sites More sharing options...
Snowman Posted December 17, 2008 Share Posted December 17, 2008 I think it's a case of switch jealousy... I recently bought my 91 Loyale and it has the FWD switch on the gearshift, and he really liked that idea. He wants to be able to switch in and out like me, I guess. I don't know if the system on the Loyale works similar to the one on the Legacy. I actually didn't think the switch would hurt the transmission, but I told him I'd check anyways. I bet he'll be happy and switched in by weekend's end. Thanks! The two systems are TOTALLY different. Your loyale uses solid gears to engage, providing true 4wd, while the legacy uses a hydraulically actuated clutch pack to engage the rear wheels. If he wants to really trick it out, he can install not only the FWD switch, but one that cuts power to the Duty C solenoid, locking the clutch pack and providing actual 4wd. Legacy777's web page documents the procedure for installing that switch ( you just need to find the right wire in the transmission control harness and splice in a toggle switch. When it's turned on, the AWD works. When it's turned off, it's 4wd). Link to comment Share on other sites More sharing options...
CNY_Dave Posted December 17, 2008 Share Posted December 17, 2008 I'm in the 'theoretically you could see an increase because the clutches will never drag against each other but realistically you won't be able to tell no matter how close you look' camp, as long as the tires are in spec, anyway. Dave Link to comment Share on other sites More sharing options...
idosubaru Posted December 17, 2008 Share Posted December 17, 2008 i've done it and noticed zero difference in gas mileage. probably not worth the trouble although i suppose his driving habits/patterns could be different than mine and maybe it would somehow be noticeable. and as for your loyale, like already mentioned it's a completely different system. is yours a manual? in that case it's comparing apples to the north pole. Link to comment Share on other sites More sharing options...
rpiereck Posted December 17, 2008 Author Share Posted December 17, 2008 I figured the Loyale and the Legacy had different systems. My Loyale has the 3AT tranny, with the selectable 4WD system. My Forester has the 5MT, which behaves completely different from the Loyale, it feels like it gets much better traction on snow and ice, the Loyale likes to spin its rear wheels on ice, and going up snowy slopes is tricky... Link to comment Share on other sites More sharing options...
bratman18 Posted December 17, 2008 Share Posted December 17, 2008 I figured the Loyale and the Legacy had different systems. My Loyale has the 3AT tranny, with the selectable 4WD system. My Forester has the 5MT, which behaves completely different from the Loyale, it feels like it gets much better traction on snow and ice, the Loyale likes to spin its rear wheels on ice, and going up snowy slopes is tricky... The difference in traction is probably just a difference in weight and tires between the two vehicles. Unless your forester also has an LSD in the rear. Link to comment Share on other sites More sharing options...
rpiereck Posted December 17, 2008 Author Share Posted December 17, 2008 The difference in traction is probably just a difference in weight and tires between the two vehicles. Unless your forester also has an LSD in the rear. I'm sure tires are a big part of the equation, the Forester has nice Blizzaks while the Loyale has el-sheapo studded tires. The Forester is also a while lot heavier than the Loyale, but I am sure the way the manual drivetrain on the Forester works provides much better traction than the automatic on the Loyale. The manual Forester proides 50-50 distribution of torque at all times, while the Loyale seems to send the torque to the wheels that have the least resistance... Link to comment Share on other sites More sharing options...
mrtoyou7747 Posted December 17, 2008 Share Posted December 17, 2008 I installed a 10Amp fuse in series with the switch - Just to be safe! BTW no diff in mileage. Link to comment Share on other sites More sharing options...
WoodsWagon Posted December 18, 2008 Share Posted December 18, 2008 Make sure the switch is just connecting the two wires that the fuse connects when you plug it in, and not feeding 12v into either of the fuse wires. It's merely a ground signal to the computer when you put the fuse in, not a load. The only advantage to a FWD switch is the ablilty to switch it in and do FWD burnouts, then back to AWD for normal driving. Link to comment Share on other sites More sharing options...
bratman18 Posted December 18, 2008 Share Posted December 18, 2008 The only advantage to a FWD switch is the ablilty to switch it in and do FWD burnouts, then back to AWD for normal driving. :lol:Yeah I used to that with my '97 impreza, It would just burn and burn and burn! wears the tires out really fast so I kept it AWD most of the time. Link to comment Share on other sites More sharing options...
WoodsWagon Posted December 18, 2008 Share Posted December 18, 2008 Totally. Put the fuse in my mom's outback (EJ25), stalled the torque converter and popped off the brake and it would annihilate the right front tire. Ride the handbrake for even longer runs before it hooks up. I have a policy of "using up" any tire before it goes to the scrap heap. Link to comment Share on other sites More sharing options...
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