Got a prius, should be interesting to mess with....

[ps2fixer]

Originally Posted by Drifter

How hot was it? If the battery temperature gets too high it won't turn off the engine.

88F day time, about 60F at night when it did the weird stuff.

Looks like there isn't an xgauge for battery temp, so I can't monitor that through the OBD2 port either.

[Drifter]

Did you try these xgauges? https://priuschat.com/threads/16-new...xgauges.49967/
https://priuschat.com/threads/update...angauge.68477/

[ps2fixer]

I was using these, didn't realize there were more.

https://www.scangauge.com/x-gauge-co...ius-2004-2009/

[bandit86]

Originally Posted by Drifter

Here is the brake specific fuel consumption map for the Prius 1.5L (Gen 2 & Prius C) and 1.8L (Gen 3, V, & Gen 4):




That dark grey "island" of peak thermodynamic efficiency occurs between about 20 & 35 KW of power (~27-47 horsepower). Here is a ballpark of the power required to overcome aerodynamic drag and rolling resistance at steady speed on flat ground for the gen 2 prius:

MPH HP
5 0.4
10 0.7
15 1.2
20 1.7
25 2.4
30 3.2
35 4.2
40 5.5
45 7.0
50 8.7
55 10.8
60 13.3
65 16.1
70 19.4
75 23.1
80 27.2
85 31.9
90 37.2
95 43.0
100 49.4

Add another ~1 hp to run all of the computers, another 2-8hp to run accessories like the water pump and air conditioning. But basically the load you put on your engine holding a steady ~80mph is the load you want to drive at when accelerating. And if you're not accelerating you should try to be coasting.

I like the speed versus horsepower numbers, can anybody put it to your graph and see what the highest average speed is at the best fuel economy? Although, if I remember correctly the tire losses are inversely proportional and they kind of get the best of both worlds at 55

[ps2fixer]

I haven't messed around long enough to really know for average trips, but it seems like driving extra slow when it's cold will help tons. If you only care about in cruise mpg vs speed, here's a chart for that. I'm hitting about 71-77% of those figures for trips based on what the screen/scanguage tells me.

I think this is the chart you're looking for. The one you quoted is hp vs rpm which is more acceleration based. It's not clear which generation the chart is for, might be 3rd gen, but 2nd gen mimics the numbers somewhat well in my experience so far, just my numbers are all down roughly the same % across the board it seems like (more at higher speeds), but my car has some light body damage and panels missing that probably hurts areo.

[ps2fixer]

Small update, got the hitch on the car, one bolt broke off so will probably have to weld that side on. The mounting brackets were just like others have said for the curt hitch, too narrow needed to be bent open more, only slightly though.

I left the rear plastic cover off for now, need to get some undercoating sprayed in there, things are starting to get a bit rusty in that area. Need to cut the notch and reinstall after that. It does seem like mpg dropped a bit from it being off though.

Also first real issue with the car, P0A93 - Inverter Water Pump Failure. From my understanding, it seems like that code comes up with the inverter is over heating. Checked the overflow and there's no signs of fluid flow as online suggests so it seems like the pump isn't pumping. I've removed my lower block and that allowed enough air to keep the code from coming back on at 55mph on the express way. Perfect timing of course, got a trip to go on that's something like 150 miles one way tomorrow. Good thing I have a 2nd prius, guess I'll be swapping a pump tomorrow before the trip and taping up the front end again.

I also got another fill up on the car now, Tank average 55mpg, not too bad for driving pretty slow, short trips and a couple trips more in a rush.

Also got a dash cam to record front and rear of the car and once I do the full install it has a parking monitoring type of setup too. Had a company van backing out of a drive way and they didn't look and just about hit me. Doubt the dash cam would have helped me get the plate number, but I contacted the company that owns the vehicle and have heard nothing back from them. I guess the company doesn't care about bad press - Senior Services of Midland Michigan.... yea it's a company that drives seniors around... It's just a bad driver, or maybe they just made a mistake, but the company doesn't even say they will look into it or talk with the driver so I know who I won't be suggesting for that kind of work... not that I really know many people that would need their service.

Update on fuel prices for my area.... gas $4.99 and Diesel $5.99. Compared to driving my LS400 and getting 20mpg, getting 50mpg+ in the prius is still costing me about the same in gas as I was paying back when the gas price was around $2/gal ($0.10/mile). Kind of crazy there's been a 250% price increase on gas since right before covid hit.

[ps2fixer]

Swapped the inverter coolant pump from the other Prius I have, pump runs, no more codes, and lower grill block put back on. Pretty crazy driving something like 30 miles one way, the overheat problem came up after around 15 miles with no coolant flow and an already warmed up engine (drove there and got almost there when it acted up the first time.

[sprechensie]

Originally Posted by Drifter

Here is the brake specific fuel consumption map for the Prius 1.5L (Gen 2 & Prius C) and 1.8L (Gen 3, V, & Gen 4):




That dark grey "island" of peak thermodynamic efficiency occurs between about 20 & 35 KW of power (~27-47 horsepower). Here is a ballpark of the power required to overcome aerodynamic drag and rolling resistance at steady speed on flat ground for the gen 2 prius:

MPH HP
5 0.4
10 0.7
15 1.2
20 1.7
25 2.4
30 3.2
35 4.2
40 5.5
45 7.0
50 8.7
55 10.8
60 13.3
65 16.1
70 19.4
75 23.1
80 27.2
85 31.9
90 37.2
95 43.0
100 49.4

Add another ~1 hp to run all of the computers, another 2-8hp to run accessories like the water pump and air conditioning. But basically the load you put on your engine holding a steady ~80mph is the load you want to drive at when accelerating. And if you're not accelerating you should try to be coasting.

wherever did you find that out ?

[sprechensie]

Originally Posted by bandit86

I like the speed versus horsepower numbers, can anybody put it to your graph and see what the highest average speed is at the best fuel economy? Although, if I remember correctly the tire losses are inversely proportional and they kind of get the best of both worlds at 55

basically, horsepower doubles for every 15 mph

[ps2fixer]

Small update, mpg has slowly been declining and I'm seeing it in the instant mpg numbers as well. Ran a bit late for getting packages out so drove "normal" 55-60mph and on the way home... holy crap numbers shot up back to what they were before ~70-80mpg at 40mph. Trip to the post office was 40mpg, by the time I got home I ended up with 54mpg average. Normally it's hard to hit 55mpg driving 40 to and back.

Pretty much all of this boils down to the car having an issue, I think it's pretty accurate to say the cat is in fact bad and when I'm driving it softly it's not firing off and just getting build up inside. Once I run it hard, it burns the build up off and fires up it seems like. I guess I need to pipe the car sooner rather than later. That could explain why ~45mph+ mpg seems so low compared to other charts.