View Single Post
Old 10-22-2021, 08:59 PM   #1 (permalink)
Master EcoModder
Join Date: Jul 2017
Location: Memphis, Tn
Posts: 446
Thanks: 308
Thanked 100 Times in 76 Posts
Transmission wear from P&G (pulse and glide)?

Hello all, I'm wondering if anyone has experience with prematurely wearing out a manual transmission from constantly shifting in and out of gear.

I used to only shift to neutral on decently long/steep hills (perhaps 10 or less times per day on my daily commute) and got 42-43 MPG average. However, last tank I experimented with shifting to neutral while going down every hill and I averaged 49 MPG over the tank for the first time. Very nice! My previous best was 45.4 MPG over the tank and that was under better traffic conditions, so the new strategy seems like a massive success.

My only concern is that shifting to neutral on every hill is a LOT of shifting, there is no flat ground where I live. There's constant small hills and I drive ~50 miles per day, mostly on country backroads.

I sort of worry that I could eventually wear out 5th gear from shifting in and out of it constantly. For what it's worth, I always blip the throttle before shifting back into gear to speed up the transmission's input shaft to as close to the required RPM as possible as an attempt to minimize synchronizer wear and, to a lesser extent, clutch wear. I'm not too worried about the clutch or its hydraulics since that's not a big deal for me to replace, but I don't want to excessively wear the transmission's internals.

Anyways, I would like to continue to experiment with different coasting and P&G strategies, but only if doing so won't excessively wear my transmission. How concerned do I need to be about this? Have any of you had premature transmission failures as a result of frequent shifting? Thanks very much in advance as always!

Last edited by MetroMPG; 11-10-2021 at 12:42 PM.. Reason: (added info to title)
  Reply With Quote