Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-27-2015, 08:18 AM   #1 (permalink)
Master EcoModder
 
Join Date: Oct 2011
Location: ellington, ct
Posts: 829
Thanks: 44
Thanked 104 Times in 80 Posts
Engine "lugging"

I got into a conversation on another board with a guy about "lugging" my focus. I had stated that I wish there was a way I could install a higher 5th gear to get better mileage and thought it could easily pull a considerably higher gear because I could easily pull slight hills at 35 in 5th.

He thought that at that speed, I may be doing damage because I was lugging it. I disagreed because, judging by sound and feel, things were still operating smoothly, so long as I didn't call down to the engine room for anything more than a slight throttle opening.

My question here is at what point does lugging cause increased engine wear? Are you fine, so long as the sound and feel are good? Are you already doing damage if you hold a gear until the engine starts complaining? Is it better to just kick it down a cog well before lugging symptoms occur?

I guess this is yet another reason to invest in a scan guage type instrument as I would think that you would see a drop off in mpg before you felt any lugging symptoms.

And for the foci owners out there, I have an 05 ZX3 5 speed 2.0 duratec. What do you feel is a minimum acceptable speed for holding slight grades in 5th? Did this come with different "rear end" ratios? The guy I was talking to had a 2.3 duratec and it sounds like he may have had higher gearing which would explain his opinion on driving 35 mph in fifth. His claim was that with his car, you could basically idle in 5th on the flats, but anything requiring even the slightest throttle opening would result in a lugging condition. I find that I can idle along on the flats at 30mph in 5th, no problem.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-27-2015, 08:58 AM   #2 (permalink)
Master EcoModder
 
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,024 Times in 1,304 Posts
The point I would even consider close to lugging is when you are climbing a grade and it gets steep enough that more throttle gets you no more speed. Combine this with the second ingredient, too low rpm and you might get closer to lugging at rpm 's below 13-1500.

Throttle position would never be close to WOT.

In the old carbed days with specific volume accelerator pumps, it was much easier to "lug" and engine by flooring it at much to low speed in too high a gear. Now you have doubled or tripled the fuel mixture, way too rich, and you can do real damage.

With modern efi that is impossible.


regards
mech

Last edited by user removed; 08-27-2015 at 09:32 PM..
  Reply With Quote
Old 08-27-2015, 10:20 AM   #3 (permalink)
Master EcoModder
 
Join Date: Jul 2008
Location: NY state
Posts: 501

XJ Cherokee - '00 Jeep Cherokee Sport
90 day: 12.96 mpg (US)

FoFO - '11 Ford Focus SE
90 day: 36.78 mpg (US)
Thanks: 1
Thanked 51 Times in 38 Posts
There's various gearing available for the MTX-75. I believe my 2011 with the 3.58 gearset is the "tallest" that was available here in the USA.

I believe there is a warning about damage that can occur to the dual mass flywheel if you operate the engine at below 1250RPM with a load.

The transmission gearing is awful though. I'd like to find a shorter first and a taller 5th. I would be happy with a very wide ratio.
  Reply With Quote
Old 08-27-2015, 12:00 PM   #4 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
I routinely climb a 1.5 mile steep grade hill in fourth (I have the super tall VX/CX gearing), which I allow to drop to 1500 RPMs before shiftng to 3rd at about 38mph. I do that at part throttle, but about 75-80% load. That is not lugging by any definition I am familiar with. The ECU compensates for fueling issues. It actually leans out the fuel mixture very nicely. Here is a good discussion on a good discussion board:
How can I tell when I'm lugging my engine? | Mechanical /Maintenance Forum | Bob Is The Oil Guy

I hope that is helpful.

James
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.



  Reply With Quote
Old 08-27-2015, 01:09 PM   #5 (permalink)
Master EcoModder
 
JRMichler's Avatar
 
Join Date: Feb 2011
Location: Phillips, WI
Posts: 1,013

Nameless - '06 GMC Canyon
90 day: 37.45 mpg (US)

22 Maverick - '22 Ford Maverick XL
90 day: 41.9 mpg (US)
Thanks: 188
Thanked 466 Times in 287 Posts
I regularly run as low as 600 RPM (18 MPH) in 5th gear. It will even accelerate, although slowly, from that speed in 5th. I've been driving that way since the truck was new. It now has 98,000 miles.

The alternator cannot keep up at that RPM, the voltage drops to 13 V.
__________________
06 Canyon: The vacuum gauge plus wheel covers helped increase summer 2015 mileage to 38.5 MPG, while summer 2016 mileage was 38.6 MPG without the wheel covers. Drove 33,021 miles 2016-2018 at 35.00 MPG.

22 Maverick: Summer 2022 burned 62.74 gallons in 3145.1 miles for 50.1 MPG. Winter 2023-2024 - 2416.7 miles, 58.66 gallons for 41 MPG.
  Reply With Quote
Old 08-27-2015, 07:58 PM   #6 (permalink)
Master EcoModder
 
Join Date: Oct 2011
Location: ellington, ct
Posts: 829
Thanks: 44
Thanked 104 Times in 80 Posts
I understand what the damage is, my question was more about when it starts to occur. Is running the engine just above the rpm where lugging symptoms occur, damaging?
  Reply With Quote
Old 08-27-2015, 08:37 PM   #7 (permalink)
Master EcoModder
 
oldtamiyaphile's Avatar
 
Join Date: May 2009
Location: Australia
Posts: 1,510

UFI - '12 Fiat 500 Twinair
Team Turbocharged!
90 day: 40.3 mpg (US)

Jeep - '05 Jeep Wrangler Renegade
90 day: 18.09 mpg (US)

R32 - '89 Nissan Skyline

STiG - '16 Renault Trafic 140dCi Energy
90 day: 30.12 mpg (US)

Prius - '05 Toyota Prius
Team Toyota
90 day: 50.25 mpg (US)

Premodded - '49 Ford Freighter
90 day: 13.48 mpg (US)

F-117 - '10 Proton Arena GLSi
Pickups
Mitsubishi
90 day: 37.82 mpg (US)

Ralica - '85 Toyota Celica ST
90 day: 25.23 mpg (US)

Sx4 - '07 Suzuki Sx4
90 day: 32.21 mpg (US)

F-117 (2) - '03 Citroen Xsara VTS
90 day: 30.06 mpg (US)
Thanks: 325
Thanked 452 Times in 319 Posts
If you take a production car to a race track you can measure engine life in hours (maybe 48hrs max). Low rpm operation is much more engine friendly. As Old Mech said, damaging detonation is a thing of the past, so IMO drive sensibly and don't worry about it. The ECU will protect you unless you're a complete tool, the fact that you even know what lugging is already puts you ahead.

My 1.6 petrol Renault will pull 5th gear at 20mph on level ground...towing a 1200lbs trailer. I wouldn't worry about what you're talking about, what RPM are you turning at 35?
__________________






  Reply With Quote
Old 08-27-2015, 10:08 PM   #8 (permalink)
Master EcoModder
 
Join Date: Oct 2011
Location: ellington, ct
Posts: 829
Thanks: 44
Thanked 104 Times in 80 Posts
Just shy of 1500. I find that I can idle along at about 25, no problem, on flat ground. By 40 it will pull a reasonably steep hill. I see no reason ths thing couldn't be geared to turn 2K or even a bit less at 60.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com