Sudden Increase in MPG/Calc'd/MFD

I wanted to post a new thread noting that in the past 2 weeks I have noticed a tremendous increase in my MPG figures in my daily commute.
I am sure there are lot's of variables, and honestly I suspect it is the RIGHT foot that is effecting my mileage the greatest, however I will post what was done recently as a barometer to what's changed.

1) 32K miles, got another oil change. Done at Dealer, will try to post part number of oil, however in the past they have always put 505.01 oil not 507.00. I noticed that it said VR6 Oil/filter kit, but it doesn't tell you spec of oil.

2) Replaced brakes, rear were sticking something awful, I burned brakes rotors, was replaced by non VW mechanic, but parts are true OEM replacements that VW/respectable mechanic would use.

3) Temperature droppped from high 90's to mid 70's/80's

4) With above temperature decrease, less use of air condigitioning

5) Traffic is less stop and go than normally experienced (at least for past few weeks)

Again, I think I have been making a conscious or at least Semi Conscious effort not to step into the floor in my stop and go Highway traffic so I think that is helping and I am no longer doing 80-90-100 when the highway is open so I think that is a major factor, however I still do from time to time.

What do you think are the major factors in increase in mileage? I think the temps/atmospheric pressure and the less intense driving.

Other variables:
I blend some B20 from time to time, basically topping off a tank that is always above 3/4 full, as I don't want to go out of warranty bounds.
Problem is, I cannot scientifically measure how much I am blending ever 2 weeks, as I just top off where I am at.. 2 weeks Ago probably did 2+ gallons, this weekend did 5 gallons.
Appreciate your thoughts.

Constants: I am always using Pilot Truck stop gas as my base fuel, don' really mix that up much (although who knows what changes in blends from week to week from their supplier.

ATLSilverTDI said:

Replaced brakes, rear were sticking something awful, I burned brakes rotors

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There's yer sign....

Rear brake 'sticking' is my first choice (and second, and third). Making ANY of your brakes throw away energy and heat you have paid dearly for by burning fuel is ALWAYS bad for mileage.

Next on the list would be to improve the method of measuring the amount of fuel put in. In order to get the best accuracy in mpg, you MUST fill the tank to EXACTLY the same point every time you wish to do a calculation. You CAN pour a gallon or two of other fuel in between times - be advised that bioD has lower energy content than USLD, therefore slightly poorer mileage - but the amount you pour must be accurately known and must be added to the total shown on the pump for your calculation. If you, or your wife 'forgets' to record the amount of fuel added (and date, and mileage), you simply have to start over and discard that data point.

Yes, I agree that measuring the amount of fuel I put in would be a more accurate method... but the BioD is more for aesthetics/bragging rights... I realize I get less MPG.. although if I put a little bit in sometimes I get an improvement.

My goal is to buy some Yellow D2 jerry cans and purchase mabye 20 gallons at a time and experiment with how many gallons I can put in before I realize diminishing returns. Here in ATL BioD is about 35-50 more than D2, and other than getting to say i run BioD and it is cleaning/clean emissions/higher lubricity properties I am not really sold on paying more money for less efficient fuel.

I guess the problem wiht the brakes theory is, even though they were replaced, my mechanic could "unstick" them. He merely lubed the cables. I need to tear apart my console and dentension the e-brake.

Honestly I think it is most due to weather/and my driving habits. The past week I have been less of a "feel the torque" kind of guy and more of a "idle in traffic to the next stop" kind of guy.

I've pulled a 41 mpg average up to over 50, largely with a modification to the right foot. It's increased my 21 mile commute time by aproximately 1 minute.

It's clearly the most cost effective mod.

ATLSilverTDI said:

Honestly I think it is most due to weather/and my driving habits. The past week I have been less of a "feel the torque" kind of guy and more of a "idle in traffic to the next stop" kind of guy.

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Variant TDI said:

I've pulled a 41 mpg average up to over 50, largely with a modification to the right foot. It's increased my 21 mile commute time by aproximately 1 minute.

It's clearly the most cost effective mod.

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__. Yupp - I think you're both on the right track.

Keep it at 55 and you'll see a massive improvement in economy

Okay we all agree the right foot mod is the best adjustment.

Regarding the 55MPH... can't do that here, in the Watermelon 500, you have to go with the flow of traffic, for fear of being run over... usually 65 to 70 is fine.

The nominal increase in mileage between 55 and 65 just isn't worth the risk.

I have cut back on my 85+ days though, and yes I agree, going 10MPH faster only nets me 1 minute quicker commute over 28 miles as everyone catches up at the stoplights/ramps.

Going to be looking at loosening the e brake as a remedy for better mileage/preventative measure from burning up my brakes.

Check under the car and make sure the e-brake actuator (on the caliper) is resting against it's stop. Loosening the cable more than that won't give you anything except a non-functioning parking brake.

The brake mechanic had it up on the lift and it wasn't always retracting against the stop. I think the cable is/was too tight and the springs aren't strong enough to pull it all the way back. Dealer won't touch it, says all is "normal". Will be checking the cables for lube and tension often.
John.

ATLSilverTDI said:

The brake mechanic had it up on the lift and it wasn't always retracting against the stop. I think the cable is/was too tight and the springs aren't strong enough to pull it all the way back. Dealer won't touch it, says all is "normal".

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I'm sorry...your brake rotors burned and dealer says all is "normal" ? Get outta town! Recommend you escalate to the district manager and beyond, until you get satisfaction here. The squeaky wheel gets the grease.... (I couldn't resist).