Percentage of odometer reading that ICE was actually running?

Someone used a vibration meter to measure run time vs total hours of driving and came out with something close to 50% IIRC.

SCH-I535

 

Here's the link:

I installed an engine hour meter | PriusChat

SCH-I535

 

Since it appears to me that the AVERAGE MPG while loading the ICE is 25. Since my car gets 55 mpg on average, I'd say the ICE runs just under 50% of the time, but that might not be good since your ICE can be in standby mode while you rake in 99+ mpg going downhill.

 

In my case, the ICE is rotating 99% of the time while moving, as my commute spends its time from 47 to 62 MPH. When not moving, no miles occur.

 

Don't forget that some of the longevity comes from the engine being spun up to idle speed then holds it there to establish oil pressure, all prior to fuel & spark.

 

Who here has ever worn out the engine in a car? I've never met anyone who could say that they did, and the overwhelming majority of people who I've seen scrap cars do it for other reasons than the engine. Conventionally powered cars also shut off fuel when coasting, so the difference on the highway is very close to zero.

Much of my commute is on the freeway, so for my use the ICE is seeing most of the miles. Hybrids are also harder on engines in some conditions. For example those who commute short distance may infrequently warm up the engine completely which leads to moisture and other contaminants depositing in the oil. I've seen as long as twelve miles before the engine comes up to temp in the past, and that's worse in cold weather.

When your average car engine can see a half million miles I really don't see any kind of longevity advantage of the ICE.

 

My '84 Omni engine wore out. 2 of the cylinders were down to under 50% power. Rings wear out. Seals eventually leak. Lines clog & fail.

Then of course, there was the matter of the clutch wearing out. No gears in Prius obviously avoids that. Heck, there's no belts either.

Notice how much easier the Prius is on coolant & oil from using them less.

 

Yup, but there is an inverter, battery, and a pair of motors. None of them are cheap to replace, fortunately they rarely fail.

Not really. A heat cycle is a heat cycle, and the cooling system goes through more of them with the engine warming and cooling several times during a drive cycle. And those who do short commutes frequently are far harder on the oil than if they had a conventional engine because the oil never gets up to temp.

 

I had a 77 mustang II with the 2300cc engine. At 80k it was burning oil. I yanked it out, completely rebuilt it, including camshaft, cam bearings, oil pump, everything that was not a bolt on part. At about 140k it was smoking and burning oil once again. Yes, I have worn out engines before and I drive like your grandmother and keep my vehicles properly serviced.

BTW they were like multi cylinder motorcycles. The rings tended to crack and prematurely wear out on the center pistons due to heat.

 

Probably should have qualified that; I was born in '85 and never spent much time with older engines that didn't last very long. I still would assert that nearly all modern engines will last a LONG time.

 

You are absolutely correct about modern engines. I grew up in the 70's when 100k miles was the magic number for it being worthless. Dealerships wholesaled those out to auctions and mom and pop used car lots. I drove a 96 Oddessy van till it had over 260k and it never used or leaked a 1/2 quart of oil between changes and got the same fuel economy it did when I bought it used with 13k miles on it.

 

For the record, babying ICE is harmful. They do well when exercising moderately (just like humans). Thus, hybrid cycle is very healthy for ICE as they spend little time idling and most time actually working.

On the other hand, IMHO, hybrid ICE is optimized for fuel efficiency and not longevity. Case in point: prius oil consumption issues over 100,000 miles.

 

Yup, and working hard at that. Just about the entire time my engine was running on the right hand side of the "ECO" range it was showing 85-90% engine load. I didn't think to check manifold pressure, but I believe that the throttle plate is wide open much of the time which makes the engine work as hard as possible at a given RPM. She's most efficient when working hard.

 

I do agree with working your ICE up to operating temperature frequently. I'd like to hear more about these engine durability problems. I'm sure has something to do with the shift to synthetic-only engine oils that Toyota recommends.

I know that it's not good for an ICE generally, to be running under-temp a lot of the time. Most engines are designed to wear properly at a set operating temperature. There's also the possibility of a buildup of water in the crankcase due to condensation.

 

The question I've always had was how far do you have to drive to warm things up adequately to burn off the condensation, etc. This especially true for exhaust systems where I see water being blown out of the tailpipe frequently. I can only imagine what that water is doing to the muffler, converter and resonators. Believe it or not, but currently my shortest trip is 5 miles @ 40mph with multiple traffic lights, so I assume the ICE will warm up sufficiently, but maybe not the entire exhaust system. If I start walking at the mall again, the trip will be reduced to less than 2 miles and I see that as a problem if that's all I do for a week or so. Once we get our Prius, I want to see just how big the back is and then I might sell my truck and downsize all the way to a single vehicle. I want to get back into model railroading and I'll need to be able to haul multiple 4'x4' sheets of plywood a short distance. Chances are Ill keep the truck.

 

A nice warm engine makes for parts that swell a bit and fit better to one another. Oil also flows better. Back when I worked on cars for a living thermostat temps went up from 180 to 192 degrees when catalytic converters and unleaded fuel came out. I have even seen 160 degree thermostats in cars made in the 50's and 60's.

 

I'd love to know how you came to that conclusion. I have the 65,000 mile UOA on my wife's Sienna after a 10,000 mile drain interval with recommended synthetic oil, and all of the numbers look fantastic. We're not easy on that thing either; it tows the boat!

There are enough stories on here of folks racking up many hundreds of thousands of miles on their Prii without any issues to speak of. It's downright rare to hear of an engine failure. I don't think there is a durability problem.

 

No conclusion, just inquiring about jacek's earlier comment: "Case in point: prius oil consumption issues over 100,000 miles." I'd like know what he meant also.

 

Spend some time in the gen 2 forums and you will know what I'm talking about.