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-   -   MDS Disable = 2mpg loss (http://www.jeepgarage.org/f5/mds-disable-2mpg-loss-10498.html)

bluethunderjeep 06-21-2010 12:56 PM

MDS Disable = 2mpg loss
 
I recently disabled MDS with my Superchips tuner.
The overall driveability has been greatly improved, however with mixed mostly city/some highway driving, I have lost about 2 mpg. Used to be 13.7-14.0, now I'm at 10.6-11.6.
Is this typical? Not complaining, as fuel economy is not an issue, or I wouldn't drive a 5.7.

TIA;

Dave

Escape 06-21-2010 01:05 PM

Re: MDS Disable = 2mpg loss
 
I'd say with your 91 tune and the MDS disabled 2mpg is about right.

jeepgcoman 06-21-2010 02:03 PM

Re: MDS Disable = 2mpg loss
 
Yep, about the same for me on the highway. Even though the driveability is better, I think, at the price of fuel these days, I'll stick the the MDS on.

1 GRAND 06-21-2010 02:36 PM

Re: MDS Disable = 2mpg loss
 
I was really excited to get the superchips on mine, but after driving it for a few weeks I decided to return it back to stock. The fuel mileage on mine went from about 16.5mpg to 13.0mpg.

LTrainGC 06-21-2010 02:49 PM

Re: MDS Disable = 2mpg loss
 
When I went from bone stock to running an intake, cat-back exhaust, and 91 tune W/MDS disabled, my MPG in town stayed the same as stock and I gained 1-2 on the highway. When I got my lift and tires (32") installed, my mileage pretty much went back to what it was stock, maybe lost an MPG in the city.

I didn't really drive it hard at all, and my "city" driving was really rural town driving... had 3 red lights on my way to work and they were usually green, speed limit was 55.

I did notice though that if I drove it hard in real "city" conditions... I could almost watch the fuel needle drop lol. So, I think what you are experiencing is probably normal, under the assumption that you have quite a bit of stop and go and drive mildly aggressive.

bluethunderjeep 06-21-2010 03:01 PM

Re: MDS Disable = 2mpg loss
 
Quote:

Originally Posted by LTrainGC (Post 224865)
I did notice though that if I drove it hard in real "city" conditions... I could almost watch the fuel needle drop lol. So, I think what you are experiencing is probably normal, under the assumption that you have quite a bit of stop and go and drive mildly aggressive.

Definitely. A quick check of the evic (for reference only, not how I calculate actual mpg) running aggressively in the city only reveals 8.6-9.6 mpg with MDS disabled.

Thanks for the replies guys! Seems to make sense then.

Dave

Walt 06-21-2010 08:15 PM

Re: MDS Disable = 2mpg loss
 
Quote:

Originally Posted by bluethunderjeep (Post 224822)
......The overall driveability has been greatly improved, however with mixed mostly city/some highway driving, I have lost about 2 mpg. Used to be 13.7-14.0, now I'm at 10.6-11.6.
Is this typical?.......

Dave

About right.

When my MDS went inoperative, interstate highway mpg went from 20.1 mpg to 16.7 mpg (EVIC comparison). Town/rural driving went from 17.7 mpg to 15.4 mpg (same measurement method).
MDS is now operating again, and I'm back to 17.7 mpg town/rural and 20.7 mpg at constant 60 mph. Haven't been back on I-75 since it began functioning again.

More operating data for your comparison survey. :)

chefalan23 06-21-2010 09:37 PM

Re: MDS Disable = 2mpg loss
 
i didnt lose any mpg's with my mds disabled (according to evic) i still avg 15.7-15.9 with mostly hwy driving. i think the 93 tune definatly compinsated for the mds disable. my only problem with the mds is the horrendous exhaust not it gives me. sounds like a rhinosaurus fart or something.

blackpepper 06-22-2010 12:08 AM

Re: MDS Disable = 2mpg loss
 
rhinoceros farts stink..

05quadratrac 06-22-2010 01:12 AM

Re: MDS Disable = 2mpg loss
 
You 5.7 guys get the same MPG I get with my 4.7. I average about 11.5 in the city and might hit 13.5 to 14 on the highway if im lucky. With autostick in the city I was getting about 9mpg letting it rev higher.

dsalinas 06-22-2010 01:29 PM

Re: MDS Disable = 2mpg loss
 
With MDS disabled my mileage pretty much stayed about the same city, but improved on the highway.

Black Betty 06-23-2010 05:44 AM

Re: MDS Disable = 2mpg loss
 
Quote:

Originally Posted by 1 GRAND (Post 224864)
I was really excited to get the superchips on mine, but after driving it for a few weeks I decided to return it back to stock. The fuel mileage on mine went from about 16.5mpg to 13.0mpg.

Aww come on bub, you gotta live a little. I hate seeing my MPG go down with my driving style too, but I can't help it. I like to make the skinny pedal and floor get intimate :)


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