Steady State Speed vs Fuel Economy results

Discussion in 'General' started by seftonm, Mar 22, 2014.

  1. xcel

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

    Hi Edwin:

    Yes they do and it helps a lot. The Corolla contingent even into the latest gen has a hair trigger throttle tip-in and I think it sucks. There is only so much performance you can get out of one and Toyota purposely added the heavy throttle response to make owners believe they are getting more go than the car is capable of.

    Mike, this week's ride is a Blue Civic Sport Hatch with the stick.

    Last edited by a moderator: May 13, 2017
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  2. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    Wow, what are the chances?
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  3. Jay

    Jay Well-Known Member

    I made this crappy graph of the new turbo 1.5L Civic steady-state data overlaid. Carcus' 6mt Civic sedan (blue line) wins by a landslide with this sport hatch CVT giving the worst showing. So what is hurting the mpg of the sport hatch the most? Is it the hatch shape? Is it the extra wide 235 tires? Is it the CVT? My favorite Civic is the LX hatchback which has narrower 215 tires and 6MT standard. That would be the one to own if you want a hatch and the best FE.

    Last edited: May 13, 2017
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  4. Jay

    Jay Well-Known Member

    Oh, another question now that I think of it: The sport hatch can take 2 fuels, regular and premium, and gives better performance on premium. Would it also get better fuel economy on premium? I think that it would because it might allow more compression. Wayne, do you remember what kind of fuel you were running?
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  5. xcel

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

    Hi Jay:

    Minor 87 fills in the Civic Sport Touring and Sport. Not sure what was in their from the Press Fleet Handlers previously.

    The Conti Pro Contact 18's, their width, and their construction really hurt the Civic Sport and Sport Touring.

    Moving to the MT, the manual offers the most efficient energy transfer by far but damn these Honda ratios are FUBAR with this powerful of a motor. Yesterday in the worst traffic in the country - read the 405 here in SOuthern Calif. - I am driving around in the heaviest of traffic nightmare down to 10 mph in third gear! Second is almost useless and first should not be used even for launch!

    2017 Honda Civic Sport Hatch - 6-speed MT

    I despise capless refueling systems. :(

    I have been complaining about Honda MT ratios forever and this is one of the most flagrant violations of efficiency I have experienced. Despite the poor design implementation, it is still the most efficient offering. If only the final was a 2.5 to 3.0 vs. the 4.105, the Civic Sport and Sport Touring Hatch with the stick could be a record setter.

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  6. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

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  7. Jay

    Jay Well-Known Member

    I was comparing the Civic hatch 6MT ratios with my 160hp 2775lb acura rsx and overall top gear of the Civic is nearly as tall as my auto rsx (which has very tall gearing). Now the Honda Fit 6MT is a real buzz bomb!:)
    Anyway, I'm very much looking forward to your results.
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  8. xcel

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

    Hi Jay:

    The Fit w/ the MT vs the AT is one of the largest Honda ratio mistakes in modern times as we all know. In the case of the 10th gen Civic with the stick, it will run at a calculated 2,227 RPM@60 mph in the EX to 2,245 RPM@60 mph in the LX. Both seem fine upfront but this motor is so powerful it is toying with these low ratios and throwing a ton away at higher speeds. To the tune of running through all 6-gears by 30 mph. I would give anything to have GM's or VWs much taller MTs in the Civic.

    Nobody matches Honda's 1.5T when it comes to low load/low RPM efficiency other than the Elantra ECO and the Gen 4 Prius lineup. I just hate to see it thrown away when the final is so short that it makes this nice shifting 6-speed stick a poorly geared 4-speed in the real world.

  9. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    Only at cleanmpg would you ever see that sentence ! I haven't owned a Honda manual since 2008 , but I'm well aware of the poor gearing choices on the Fit. That car has SO much potential , for either efficiency or performance, but Honda chose the "one-size-fits-all" approach.
  10. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    It really does fall flat on the highway. I'm at a redonkulous 2900 at 60 mph. Thankfully I rarely need that kind of speed. The highest limit on my commute is 50 and it's a multi-lane road so I can keep below that.
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  11. Carcus

    Carcus Well-Known Member

    I'm not sure I agree here.

    At least not for the 6th gear usage by 'average' highway cruisers, .. the ones who just set the cruise control somewhere near the speed limit and forget about it.

    At 65-70 mph (and higher) If I bring the turbo gauge up, I will notice 1 or 2 or 3 bars of boost when going up lightly rolling terrain, especially with head wind. I suspect same speed at lower rpms (i.e. with a taller final) the average driver (who doesn't know or care to drive with load (i.e. let the speed sag uphill and catch up downhill) or *gasp* downshift -- would see more boost (3 or 4 or 5 bars) and quite possibly lower overall highway mpg. Once up at highway speed, the rpm piper or the turbo piper will have to be paid, I'm not sure which one is more expensive.

    Just imo,... I guess you'd have to see some real world "different gearing" testing or some high power computer simulation (which honda surely has) to know the real answer.

    /speaking of real world testing.... Wayne, were you able to collect steady state numbers on any of the 1.5 6mt versions?
    Last edited: May 18, 2017
  12. xcel

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

    Hi Carcus:

    Good stuff and this weekend. :)

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  13. alster

    alster Well-Known Member

    My 1994 Honda Civic VX ( the rare model that obtained 50+ MPG) had a 5 speed manual and a 1.5 engine with 92 HP. RPM at 60 MPH was right around 1900 rpm or so. I would have to believe
    that the new Civic 1.5 with 174 HP could be turning 1500 RPM at 60 MPH with a manual tranny, and near 60 mpg should be your return as well, even though it weighs 700 lbs more or so than my 94 Civic.
    I think Honda missed being number 1 for a non hybrid fuel economy champ by the 1.5 engine with the manual trans. revving too high..
  14. ALS

    ALS Super Moderator Staff Member

    With your discussions concerning Honda and their poor gearing decisions with the manual transmissions maybe someone should send Honda Engineering this article from April 1967.

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  15. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    In the old days when they said "low" or "high" axle ratio , they meant numerical. A 3.07 axle is a higher gear ratio than a 3.90 , but lower numerically.
  16. Carcus

    Carcus Well-Known Member

    Interesting article, but I'd say Honda was already aware,... and decided to pass on the '6.5 liter solution' to the friction problem ...

    2016 Honda Civic Drivetrain(s) Deep Dive
    "Friction Reduction

    Both of Civic's engines make use of new friction-reducing technologies designed to improve engine efficiency. The outer skirts of lightweight aluminum pistons feature a low-friction coating applied in a unique pattern. The result is reduced overall friction as the pistons move within the cylinder bores. Plateau honing lowers the friction level between the pistons and the cylinders by creating an ultra-smooth surface. Plateau honing is a 2-stage machining process that uses two grinding processes instead of the more conventional single honing process. This also enhances the long-term wear characteristics of the engine. Low viscosity oil (0W-20) also reduces friction. Other contributors to overall operating efficiency are a special two-stage oil pump relief valve, low-friction oil seals, special low-drag piston ring design, low-friction cam chain and a lightweight crankshaft. "
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  17. ALS

    ALS Super Moderator Staff Member

    The point was the engine friction created by running higher than needed RPMs at 60-65 mph.

    They may have been talking about a 400 ci motor in this article but the same friction and pumping losses also apply to a 1.5-2.0 liter motor.

    When I modded my old Volvo wagon for fuel mileage the biggest gains were from lowering the rpms and cutting drive line power losses at higher speeds.
    Stock 340 miles per tank to 425 miles per tank after mods at 65 mph.

    As Wayne pointed out above,
    There is no reason for Honda to gear the Civic so low. With the Civic's aerodynamics today and its low friction drive train, there should be zero problems running 250 rpms lower at 60 mph. They could easily run a Civic at 1850 rpms at 55 mph.
  18. seftonm

    seftonm Veteran Staff Member

    The Civic 2.0 and 1.5T use the same manual transmission gear and axle ratios, despite having very different powerbands. The gear ratios seem to be a compromise, with one of the requirements being to keep the 2.0 near its powerband in top gear.
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  19. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    They certainly could. My 08 Civic was right around that RPM at 55 , but it had much less horsepower and torque. Why not 1800 RPM @ 60 MPH ? Do you hear me , Honda ?
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  20. Jay

    Jay Well-Known Member

    Speaking of pumping losses and intake vacuum; how does that work for a turbocharged engine? Is there intake vacuum ever?
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