Super Highway Mode and Ignition Timing

Was Uncle Wayne referring specifically to GenIII? SHM was much easier on GenII Prii, and Honda Civic Hybrids of the same era.

 

This is a thread I found on CleanMPG that seems to cover the subject well.

 

Note that thread is for GenII, 2004-2009 models. Look in later threads for Uncle Wayne's GenIII comments. I seem to remember he found SHM being more difficult, with less usefulness and benefit. And because of the different engine, it had different TPS and IGN numbers.

I have his GenIII SHM numbers written down somewhere inside my car, but don't use them. I'll try to dig them up tomorrow.

 

If you are using a Scanguage in a Gen 3 try and move the accelerator to hold an ignition level of 19 to 23. It will work in flat areas as well as downhill. You should see the mpg jump up to 75 mpg or better.

A secondary level that is much harder to hold is ignition at 15 which provides little or no engine motive power and may initiate fuel cutoff.

Hope this helps

 

Anyone know what the Ignition Timing PID is called on Torque?

 

I believe it is Timing Advance.

 

It is useful on flat areas and small downhill for the 19 to 23 ignition range. The ignition range of 15 relates to the warp stealth you mentioned.

Going uphill you might see an ignition level of 30. It does not lend itself to going uphill. You switch to other methods, on the fly as the terrain dictates. Going uphill you can use a driving with load technique related to RPM or kw.

Sometimes I use a floor for instantaneous mpg and keeping increasing the accelerator position until I hit a specific mpg of say 35 mpg uphill and will not add any more power. Of course it depends on the grade and traffic conditions around me.

Keep playing with it and see what works for you.

One other point. The cruise control does a pretty good job on flat areas and small downgrades. Larger upgrades are the problem with the cruise control. Try putting the cruise control on and keep track of the scan gauge in the flat or downhill areas. Many times it does a nice job locking in the appropriate ignition levels until you must go uphill!

 

That's correct.

 

You might want to look at the review of wayne's Prius c superhighway test drive in California on cleanmpg's forum. IIRC he modulates his throttle so that the ScangaugeII xgauge LOD is from 70 to 80 while going between 50 to 65 mph using driving with load. A the end of the trip the warmed up Prius c onboard fuel consumption display estimated +80 mpg .

 

Hi WaltD, what is the average speed on the straight parts if you keep the engine between 12 and 13kw? I seem to average about 65-67 mpg driving at 60mph held by CC. If you get about the same speed than it might be interresting technique.

 

After warm-up, choose the mileage by selecting the cruise control speed:

These are easily reproduced using a stock, 2010 Prius on flat roads in similar, dry conditions. Nothing to study or distract from safe driving. There are enhancements:

• fully inflated tires
• wheel alignment
• shift into "N" instead of downhill regeneration . . . using energy flow to detect
• change transmission oil

I was about to write "GOOD LUCK" but this basic engineering,
Bob Wilson

 

Hi Bob, so driving at 60mph and getting 65mpg (indicated so that corresponds to your chart) is the max I can do on flat road?

I was still hoping that I could get more with some special techniques.

this was my first tank but it was heavy raining on one way of about 40miles where I got average of 47mpg.
Details: Toyota - Prius - Prius - Spritmonitor.de

thank you
best regards
Andrej

 

Actually 60 MPG at 60 mph is more accurate assuming no other externals such as head or tail winds or altitude changes. For 65 MPG, 55 mph would work better.

Good luck!

I know the MPG vs mph chart is accurate and reproducible but there are tweaks that can help:

• low rolling resistance tires at maximum sidewall - make sure to check the odometer calibration
• wheel alignment (only if off)
• transaxle oil change and engine oil
• experimental - partial bumper air inlet block, flush to front to reduce drag at high speed

But these are going to be in the 1-2% range, at most 1 MPG each. Together, they help but run the experiment and find out.

Bob Wilson