AndyB and KenE — I must correct a statement that I made in my post #50 above (to which I have also added some PSs). The Oak Ridge National Laboratory Report referred to in the PPS to my post #50 says on pages 39 and 40 that the transaxle's lubrication oil pump is in fact driven by the ICE's output shaft and not by the transaxle's output shaft. This means that one of the two means of lubrication of the transaxle is indeed ineffective when the ICE is not rotating, such as when coasting in fuel-cut at speeds below ~64 km/h (~40 mph).

Stan

 

I let my foot off the gas at 55 even going downhill. The scan gauge shows me using .02 gallons per hour and the engine idling at 980 rpm. To me fuel cutoff would mean 00 gallons per hour with no rpm showing on the ice.

Any coasting with the engine shut off is a good way to gain mpg.

 

I have coasted in neutral up to 73/74 miles per hour with no problems. I usually wait till the car has slowed to about 60 before putting in back in drive.

What I don't understand is when I move the lever to drive, its a very smooth transition and the engine rpm slowly comes up on the scan gauge to what speed i'm driving. It's like the ice was turning all along even in neutral. The scan gauge don't show any rpm or gas usage. But the ice could very well be freewheeling. After all the engine has the trick variable cam, low friction pistons and rings. Low tension valve springs and light valves.

I have coasted in neutral that same 16 miles with no indication of the ice running. That don't mean it isn't turning. I see some belts on the front of the ice. I may mount a wireless camera there just to see what the ice is really doing when i'm in neutral when coasting.

 

i too have a scangauge with xgauge. when in ev mode under 39-42 mph, it displays 0 rpm but shows .03 or .04gph, with a mpg that varies dependant upon speed; the higher the speed, the higher the mpg. i know im in ev mode as the mpg display is in the e mode range. is it a problem with the scangauge or could there be a problem with obd2 info? i checked it with a dfferent scangauge with xgauge, and it showed the same info. both scangauges were hooked up in parallel and both showed .03 and .04gph with 0 rpm. any ideas?

 

I have only the scangauge. I had mine upgraded to the newest version. After that, when the engine is in the EV mode it still shows a trickle of gallons per hour reading, but the rpm is zero. My thinking is the engine may still be spinning but the ECU is not reporting the rpm due to it not having compression and ignition at that time. I would think in the EV mode there should be zero gas input to the injectors.

Could it be in the EV mode they close the intake valves and hold open the exhaust to prevent compression?

 

I have only the scangauge. I had mine upgraded to the newest version. After that, when the engine is in the EV mode it still shows a trickle of gallons per hour reading, but the rpm is zero. My thinking is the engine may still be spinning but the ECU is not reporting the rpm due to it not having compression and ignition at that time. I would think in the EV mode there should be zero gas input to the injectors.

Could it be in the EV mode they close the intake valves and hold open the exhaust to prevent compression? That is if the engine does spin in the EV mode or neutral.

 

I have only the scangauge. I had mine upgraded to the newer version. After that, when the engine is in the EV mode it still shows a trickle of gallons per hour reading, but the rpm is zero. My thinking is the engine may still be spinning but the ECU is not reporting the rpm due to it not having compression or ignition at that time. I would think in the EV mode there should be zero gas input to the injectors.

Could it be in the EV mode they close the intake valves and hold open the exhaust to prevent compression? That is if the engine does spin in the EV mode or in neutral.

 

I believe Ron has a firmware upgrade to ScanGauge to comprehend Toyota's fuel cut. To check it for older scangauge, check for ignition advance of 5 degrees. This is the the IGN gauge on the scangauge, and when it reads 5, there is no gas getting squirted into the injectors. Or suffice to say I've never found it reporting 5 when fuel was being squirted into the injectors.

Most fuel consumption is calculated based on vacuum pressure so if you have vacuum pressure and no fuel, it will still read non Zero for GPH.

11011011

 

Correct. I don't use a ScanGuage, but because I work in Aerospace, my car has a true fuel flow transducer that I got from the company and put in (and a triple tach, by the way). When the car is in fuel-cut (ICE off above 42 MPH) the fuel flow is zero but the ICE is showing some RPM, usually between 900 and 1200 RPM at most "normal" road speeds.

 

The "old" ScanGauge (SG) reports an incorrect (positive) fuel-flow reading when the ICE is in fuel-cut (i.e., ICE being spun by MG1 but no fuel actually flowing). The new SGs have the capability to set the TPS setting below which SG will "null" the fuel-flow to zero when the ICE reports that it's open-loop. My experiments so far (I haven't had my SG updated yet) indicate that this adjustment should be set at '16' for the TCH. The ICE RPM should continue to show that the ICE is spinning ~1000 rpm when you're coasting in fuel-cut in 'D' above ~64 km/h (~40 mph). But with the correct TPS setting of '16' the fuel flow should now read zero and the mpg should read 'infinity.' This is my understanding. Let us know if this TPS setting of '16' is correct.

Stan