For those of you who have mod'ed (and I assume that most of you in this forum), how did the mod's affect your mileage?

I'm mostly interested in data from MCSC's from before and after specific modifications. I'm less interested in the absolute figures (i.e. I get 27 mpg now!) and more interested in the relative values (when I went from stock to 210whp/195lbs, my average mileage dropped from 31 mpg to 6mpg! ).

I'm still considering mod'ing, but I'm not interested in significantly affecting my mpg. And, before we get into it, I realize your driving style counts for more than anything else. That is why I'm interested in relative figures.

That said, if your driving style has significantly changed due to your mod's (i.e. having too much fun going fast), then I'm less interested in your relative figures.

I hope this doesn't sound too specific or demanding. Thanks in advance for any help/insights you can provide.

Ivan

 

ive never really payed too much attention to how many MPGs im getting. even when i bought the car and it was stock. honestly i dont care. If it needs gas, ill put gas in it. but since a 15% pulley, 2% crank, Alta CAI, Jcw software, and a few exterior mods i seem to be at the pump more often. My cooper is a "fun" car and i only drive it every few days or when the weather is good, but whether its my driving or the mods or both, its preeetttyy thirsty these days. and yet i still dont care. i will never ***** about how much i spend on gas cause i have so much fun in it. If i were you i would still get mods and up the "fun" factor

 

I have 15% pulley, DDM Intake, On-ball exhaust, and lighter wheels.
After the wheels I noticed a small increase in fuel economy, nothing really measurable, mostly perceived, and after all the engine upgrades I lost maybe one mile per gallon. Under steady cruising my indicated fuel economy seems the same (so long as I'm traveling at legal speeds, it indicates much lower as the revs climb) I think if I didn't use the extra power quite so much I think I'd have the same fuel economy or maybe even improve it slightly.

 

I have an 06 MCSC. Installed an M7 16% pulley and ProMini CAI so far. I've seen no impact to fuel economy. I average 27 mpg.

 

I get 6 mpg on the track .

 

On road trips.. average speed is between 80-90 mph .. stock got 29+ MPG!!
15% pulley/ CAI.. same speeds.... 27-28 MPG
The above with Thumper Ported HEAD.. 28+ mpg!!

IF I slow down to 70-80 MPH.. I can pick up another 1 to .5 MPG!!

My road trips are 500 miles to Va/ the DRAGON/ Key west... blah..blah... so a good travel and average!! Me?? LOVE IT!!

Just me..........................

Thumper

PS: one-ball exhaust.

 

I personally think that if you are worried about what fuel consumption you are getting you shouldn't be modding the car. Once you modify the car you are modding it to go faster, to go faster you need to give it more gas. So A + B =C More Fuel Consumption!! These cars, once modded, are very hard to keep the foot from mashing the pedal to the floor!!

 

(by year)
Before CAI/pulley 28.2,28.3
After CAI/pulley: 29.1,28.7

Definitely more dependent on driving conditions/style than mods.

 

I get 18 around town but then again im raping on the car pretty hardcore.

 

Hmmm, I drive about 100 miles a day. I have pulley, intake, exhaust, RMW tune, and I get about 260 miles with 1 gallon left which the on board computer says my range is about 30 miles--until I stomp on the gas, and it then says 20 miles, lol. So if I said 260/12 gallons (1 gallon left) that comes out to a wonderful 21.6MPG. Fill up cost me $49.26 today...not fun when you do that more than twice a week--but super fun to drive between fillups, lol.

 

Thanks for the replies. Let me see if I can sum up what I've read so far:

1. More power equals worse mpg (A + B = C)

2. Depending on your luck, your mpg will either decrease 1 mpg (Thumper460), stay the same (Flats) or increase 1 mpg (Eric_Rowland)



Somehow, I feel like I'm missing some useful data points.

Does anyone else have pre-mod and post-mod mpg numbers when their driving style didn't significantly change?

Thanks again.

 

sums it up nicely. You can't have both.

PS - My avg since owing the car is 23 mpg.

 

I need to do some calculatin' to prove it, but since getting non runflats, my mileage seems much better. No doubt cuz the runflats couldn't hold any damn air!!! : )

 

stock '03 MCS; currently has about 67K miles... mid-high 20's around town, low 30's on hwy trips... installed ProMINI CAI practically when new.

added Helix 15% pulley, JCW exhaust a few of years ago. Mileage basically unchanged. Pulled a best of 34 mpg during The Great Ice Cream Run (FL to ME) last year.

Driving style is everything. I've yet to meet anyone who drives as smoothly as Jerseygirl.

 

I should add that when I had my 2003 Cooper, I was also getting about 22 to 24MPG and the problem was all with the driver!

 

I don't necessarily agree with this, but I may be the only one who feels that way.

It seems to me that everyone who mod's their car does so to improve their driving experience (i.e. because they want to have more fun). It doesn't seem incompatible to that goal to both want more power without losing mpg.

I realize that you necessarily burn more fuel to generate more power, so clearly, if you are consistently taking advantage of that additional power, then your mpg will always be lower. However, if you want that extra power for "once-in-a-while" bursts, then you may be able to run with a similar mpg as previously while still having the option to take off if you want to.

That's what I'd like to end up with. A car that, if I drive it nice and smoothly, still gets close the mpg that I get now, but when I feel like taking off, will allow me to do so.

It seems funny to me that everyone worries so much about high whp/torque numbers, but not at all about the mpg. If I told most people that you could have a car that has 300whp/200lbs and gets 100 mpg when you're babying it, I think they'd take it over a car with the same power, but can only get 10 mpg no matter what.

Obviously, those numbers are an exaggeration, but that's part of the reason I'm trying to collect data--to understand the range of possibilities in mod'ing. Not just for power, but for overall performance of the car, including mpg.

Again, any thoughts, data and insights are welcome and appreciated.
Thanks

 

i typically get 21-23... otw to amviv i followed a buddy with the cruise control on (prob the first time i ever drove more then 50 miles with the cc on) and got about 31mpg.

It's all about how you drive... if you can manage to keep out of the boost and leave the cruise on any time you're on the highway you'll do quite well. In town with a supercharger you're pretty much boned no matter what you do. I can never manage to put the cruise on... even though i know i should, I still manage to burn 1/4 tank running from Santa Monica to the OC when with the cruise i could do it on 1/8th.

 

iblack, no you are not the only who feels that way. I'm looking at developing a mod plan as well and one of the considerations will have to be fuel mileage as my MCS is also my daily driver for my commute to work. So I need to maintain decent mileage to keep that expense down. At the same time, I'm hoping to add to the fun factor when I go on weekend drives and other events (and the occassional need for that burst during the normal commute).

Good thread so far - will be keeping my eye on it.

 

Stock - low 30s, in the summer, taking it easy in mixed driving.
15% cai exhaust - 2-3mpg lower, 29-30mpg same conditions above.
All of above plus injectors - horrible
All of above plus tune - so far, 29-30mpg with winter gas, mixed driving.

I'm expecting as good or better than stock during the summer with the tune. (I've always gotten a 2-4mpg decrease during the winter.)

All of these figures are mixed driving taking it easy. When you flog it, the modded car will be getting worse mileage.

 

My point and the same as others have pointed out--it's not necessarily the mods that drastically reduce fuel economy, it's the driver who now drives more spiritedly because the car permits it.

An intake won't reduce fuel economy, but stomping on the gas to hear it roar will.

Richard

 

For normal freeway travel I lost 4 to 5 MPG. And for spirited driving I lost about 10 MPG. I guess that's not too bad considering I went from 167hp to 302hp!! If I did the speed limit on the freeways I could get over 30mpg with that ol' bad boy...just had to stay away from boosting.

And, yes, I've always been concerned about MPG: thread 1
thread 2
thread 3
thread 4
thread 5 be sure to check out post 16 to see how **** I was about keeping track

 

The thing is that even a low mpg Mini beats out gas wise most of the cars out there. I only get 23 mpg but get better gas mileage than most people in the neighborhood and thats why I don't care about MPG. I use less than anyone else while ringing out my MCS.

Knowing that more power equates to more fuel then its relatively a moot discussion of HP to MPG for as you point out if you don't use it then you don't burn more fuel hence no loss in mpg. So at the end of it all - discussing MPG and HP mods is unrealistic because the main factor is the driver and driving style.

If you want great gas mileage w/ just the occasional extra power then NOS should be considered.

 

This may be the root of my question. I'm (obviously) not a gearhead and therefore don't fully understand the effects of a given mod on the overall performance (and efficiency) of a motor. Perhaps a relevant question would be "which mods necessarily use more fuel". By "necessarily" I mean which mods use more fuel than the stock regardless of how the car is being driven.

I realize that driving style is more important than the mods (as I believe I mentioned originally). That's why I only asked for data from those people who haven't significantly changed their driving style--otherwise the data isn't relevant. I also asked for relative changes to account for different driving conditions (i.e. highway versus city).

This is very useful information. I know very little about NOS and it's effects on the engine (other than increased power). Does anyone have a minute to explain the pros/cons of NOS versus other power-increasing mods?

Thanks again.

 

All too close to home. I ran out of gas once in my Miata at a track day, before lunch. I was letting a buddy drive it in the novice group while I did double duty in a faster group. I got better mileage in my Ram 1500 with a Hemi pulling the Miata to and from the track.

I'm afraid my response to street driving with mods, iblack, won't be much more help. I just got my Mini about a month and a half ago. According to the computer, strictly suburban driving (very, very little highway) had settled in right around 22, pre-mods. I put an intake, pulley and exhaust on about two weeks ago and mileage dropped, into the 20.xs.

However... it seemed as though the computer may have been adapting to the mods and the quickly blackened exhaust tips might be evidence to this. I'm sure some of the others here can support or refute that observation. So, far, on the last tank, it seems right about where it was pre-mods.

I don't drive with a light foot and I take roll call each and every day of every pony in the stable. However, the novelty of the mods may be wearing off so I may not be in the throttle as much on this last tank. (Time for more mods! )

Unrelated: For the record, the Magnaflow is nowhere near *too* loud. Even my wife said, "You don't really notice the exhaust that much over the supercharger whine now..."

 

She's a keeper