TDI hypermiling tips

Discussion in 'Fuel Economy' started by garyk, Jun 10, 2015.

  1. garyk

    garyk Member

    Hi all. I thought I'd throw out a few questions after reading all I could here, at TDI club, and ecomodder about TDI hypermiling in particular (including the cool passat record-breaking threads!).

    I feel like I'm definitely gaining efficiency with pulse and glide(ICE on). I share my car with my wife and have been practicing for several months, but never sure what I was really getting given that she has about half of the miles (at 80 mph :rolleyes:). My first tank to myself in a long time I got 59 mpg, and this current one looks like it will be about the same. I can definitely improve my city hypermiling, and the mornings are still cold here, so hoping that will help some more as well. My commute is variable with one fairly steep pass (1100 feet elevation 5 miles each way), some city/hwy, and some rural roads which seem great for P and G.

    I was wondering if anyone had thoughts on three tricky parts of my commute.

    1) The big pass. It seems too long to DWL, so I end up just sticking it at 57 mph (about as slow as I can take it with my taller 5th gear). I guess that's all I can do here? It is steep enough to be in gear basically all the way down to the stop sign so that helps.

    2) Rural roads/?mega P and G? I actually have a decent part of my driving on 50-55 mph psl roads where I could do just about anything depending on time of day. Is a hugely "wide" P and G beneficial? I've seen people recommend 10 mph to 15 mph spread. I could theoretically do 20 to 60 mph P and G. Do you get burned by the lower gears or just shifting? My taller 5th gear kind of hurts me here as well I think since I kind of lug if I try to start pulsing much below 48 mph or so... I often end up gliding down to 30-35 mph and doing a 4th then 5th gear pulse up to 55.

    3) P and G acceleration. It seems this one has been beaten to death, but I'm not sure anyone has ever definitively answered it. Is the current consensus still just aiming for 70-80 LOD ?


    My scan gauge is wonky with P and G (pending fix as per other post in this forum), hopefully that will help me in all these respects if I can quash those 9999 errors.

    In the meantime, any thoughts on these things I'm still figuring on would be much appreciated.

    :) Gary
     
  2. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Gary:

    On the steepest climbs, drop back into the 30 to 35 mph range in 4th or 5th and climb in the truck climbing lanes.

    Never use a high load acceleration without the glide to accompany it. For heavy traffic, crawl up and smart brake to extend your glides into lights with the possibility of catching a clear intersection.

    Be careful what you read on other sites. I have read some truly piss poor advice on both TDIC and EM with regards to FE improvements and especially with vehicles the posters have little experience with.

    Best bet is to ask said poster what his lmpg is in that car for an idea if he or she has the faintest clue what they are talking about.

    Met up an EM member in Iowa while on the Shell DualFuel Charger drive last week. He had the lean burn Civic motor and taller final plus a fart pipe. He mentioned his best tank was 52 mpg... Not the kind of guy you probably want to listen too but at least he was pushing to improve.

    IHTHs?

    Wayne
     
    Last edited: Jun 11, 2015
  3. garyk

    garyk Member

    Yes very much thanks! When you say "high load pulse" I'm assuming you mean the 75-80? Speaking of bad advice, some of that sounds like really high load pulsing I think. That does make sense, why waste a pulse if you're in traffic and not necessarily going to be able to do repeated glides...

    I"ll try the 4th gear at 35 or so, as the taller 5th can't go any slower than 57 on that grade.

    Any thoughts on huge interval P and G vs 10 mph split?

    Thanks again!Gary
     
  4. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Gary:

    Glad I could help somewhat...

    P&G with a 13 to 15 mph interval is a decent place to start but it is also dependant on traffic, topography and your current speed. A 10 to 15 mph differential at 70 will probably cost you whereas a 10 to 15 mph differential at 40 to 45 in suburban traffic would do wonders.

    More importantly however, do not rely on a P&G cycle to achieve the highest efficiencies. Sometimes 1,100 to 1,200 RPM while DWL and looking for smooth pavement in the suburbs or Interstate jams provide a similar final while making your own daily grind less intense.

    You have an entire tool box of techniques to use at various speeds, topography, traffic conditions and road speed. Use the right tools in the box vs. the single one on the work bench. Your results will prove to be much higher than your contemporaries and you will be far better off in the process.

    Wayne
     
  5. garyk

    garyk Member

    Great advice, thanks again. I think once I realized I was getting better mileage with P and G I have tended to become a "one trick pony" with it, even in some settings where you might be better off without. Much of my commute is well suited to P and G, but I think in the city traffic at times I might be prone to slacking off, doing rote P and G and not thinking about what might work better, since the scan gauge numbers aren't as pretty. But of course, a small "save" in city traffic adds up to a lot more fuel than a perfect pulse in the country...

    I will say that I've had this car for 10 years, and the last year has been by far the most fun, all because of hypermiling. I can't thank you enough for all that you do and have done to inspire me and so many others, it's truly a blast!
    Gary
     
  6. jefflindsay

    jefflindsay New Member

    Wayne,

    I bought a 2015 VW Golf TDI S. What did you do on your test to get the numbers you got? Did you find a sweet spot as far as speed ect...?
     

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