Malone Stage 2 / Rawtek MPG Concerns

2013 Golf TDI: Last weekend I tuned and deleted my vehicle. I'm still going through my first full tank since doing so. I'm at around 270 miles on this tank with 9/16 of a tank left. I usually hand calculate my mileage but so far MFI is showing about 6 mpg less than what I'm used to and it's concerning me. It was taking about 15 miles to fully warm up so installed a winter front. MFI has jumped 2-3 mpg since doing so. I have not changed my driving habits to dig into the new found power, I got that over with at the end of the previous tank. Ambient temps are 30-40 degrees. My commute is 90% highway at 65 mph.

I'm too impatient to wait for the whole tank to see actual mileage. Any input would be appreciated.

The MFI isn't always that accurate, it'd be best to go off miles driven vs gallons of fuel added.

That's what I always do, but MFI is showing a 6 mpg decrease which is making me wonder what's going on. Also around 1/2 tank I'm usually in the 300 mile range which doesn't seem likely at this point. I'm hoping I'm just over thinking and will see the mpg gains I was expecting.

270(9/16) = 151.875
300(1/2) = 150

If you get 270miles to 7/16th of a tank then you get approx 38.5 to a 16th.

38.5*8 = 308.5 miles

overthinking it, enjoy the car

onewontwo said:

I'm too impatient to wait for the whole tank to see actual mileage. Any input would be appreciated.

Click to expand...

wait for the whole tank to see actual mileage.

Remember, it might be your driving style, too. I had pretty bad mileage my first couple tanks after I tuned my 2011, but that was because I was vape-bro drifting everywhere.

My MFI was indicating WAY higher than hand calculated - I was seeing 52mpg on the display at 80mph. Hand calculation with filling to the lip has shown on several repeat tanks and all-highway routes that it is doing about 40mpg at 80mph. I do think there may be more fuel savings to find as the back end of the car is starting to collect soot now - yes I know that is happening instead of it being trapped / stored.

My setup: 2014 JSW 170k miles, rawtek pipes but second cat (after flap) and muffler still in place.

I should mention - after about 3-4 tanks, it does seem that the MFI has adjusted itself and is reading more accurately to reality. That is a refreshing change from other manufacturers where the screen reads at least 3-4mpg high all the time.

I will provide an update when I fill up. It should be by the end of the work week.

I've got a 2013 Golf too. Bought it last Dec. 27th. I watched the MFI numbers and they weren't very encouraging, at 70mph (GPS) it showed 35-37 on flat level road, using my GPS with altitude. Maybe a variance of 1-2' over a 100 foot stretch. My first fill up with the Golf gave me 36mpg! Not very happy at that point. WTH?



About half way home a week later from the dealer, (had to get those keyed lugs off, and no keyed socket to be found!) so I could swap out the summer tires to winter treads, the CEL light came on. WTH? So I called the dealer a few days later with two problems, the CEL, and a weird 'hop' while turning into a 25-30mph+ right hand corner, and during moderately quick accelerating in a straight line up to about 50 or so where it smoothed out.



That ended up being a bad R/H axle. WTH? 25k on the speedo? When the service manager read the codes, yes, two codes he informed me that the EGR AND the DPF were both bad and needed to be replaced, and by the way, axles come from Germany, and it might take a while. I went home in a courtesy car. Three weeks to the day left my car there it was ready to be picked up.So now I have a new EGR & DPF equipped car. And it seems like more power too.


This is a 25k mile CPO car! Anyway, the MFI numbers are well into the 40's at 70mph, with GPS, on flat roads. At a steady 50mph the MFI shows 55-60mpg. I don't drive much this time of year so I still have 3/4 tank left after that trip to the dealer, an 89 mile one way trip. The MFI numbers are 10-12mpg better than before the EGR & DFP replacement at freeway speeds of 71-72mph indicated, no GPS on that trip. I know the MFI numbers aren't all that accurate, I'll know more after the next fill up.



Here's the link to Fuelly and my Golf numbers, NOT GOOD!



http://www.fuelly.com/car/volkswagen/golf/2013/quadaffyduck/880800



My 2013 Jetta TDI Premium (also DSG) that I turned in on Dec 22nd, 2016 averaged 40.1 over 22k miles in 3+ years of owning it. I use Fuelly to keep track. That is about 50/50 city/highway. I was quite happy with that number. I'm hoping the Golf will eclipse those numbers, most Golf TDI's do. I 'think' that service manager did something to the ECM, not sure, but he did say I should see much better than 36mpg, and he said it with a sly wink.



Hmm... Much better power, and the MFI numbers are quite encouraging. We shall see.

Not sure what the service manager could have done other than the factory tunes... But I'd be curious what codes exactly the car had tossed. I suspect that VW has declared that many of the emission related codes will result in just swapping out everything as it is cheaper to do that than piss off the EPA again.

The MFI may take several tanks to recalibrate if there was a significant difference. Mine seems to have stabilized and reads about 44mpg as an average, since most of my driving is highway, that could fit. With a large percentage of city mileage on this last tank, my hand calculation said city mileage was 34mpg.

At 320 miles the fuel gauge was straight up, 1/2 tank. I'll wait until I'm at the warning light to fill up unless I'm traveling between towns in an unfamiliar area.



Manufacturers always fudge on their fuel gauges, 1/2 tank ls more like 1/4 tank left. Makes you think you're getting superior mileage when you really aren't. That last half goes twice as fast as the top half of the tank. I wish they'd make 50/50 at half tank. I've damned near run dry a few times while adjusting to a new vehicle. My 2013 Jetta was the same way. As is my Miata.

So I filled up today and hand calculated 45.7 mpg. It was my first 600 mile tank so I'm pretty excited about it. MFI showed 38.7 and it used to show 1-2 mpg high. Also the range upon filling showed 550 and used to 600 every time.

Just odd how much things have changed but I can't really complain with that kind of mpg gain. I expect to be even better this tank since adding the winter front.

What's a gallon of fuel cost 2.49 here in Texas? You're fine. Get a scan gauge if you want to geek out over mileage. Should see another 1-2 mpg at least with that tune and free flowing exhaust

Sent from my FRD-L14 using Tapatalk

I don't know about other platforms, but on my 06 Jetta BRM I was able to adjust the MPG indicator with VCDS. Previously it used to indicate about 10% more MPGs than reality. I have adjusted to the max and now it's only +-1 MPG wrong. Also the speedometer can be adjusted.

onewontwo said:

So I filled up today and hand calculated 45.7 mpg. It was my first 600 mile tank so I'm pretty excited about it. MFI showed 38.7 and it used to show 1-2 mpg high. Also the range upon filling showed 550 and used to 600 every time.

Just odd how much things have changed but I can't really complain with that kind of mpg gain. I expect to be even better this tank since adding the winter front.

Click to expand...

Your ECU takes a little bit to adjust to the tune, so it make get closer to the true mpg after a couple tanks.