Caution PHEV owners. Extended EV use and high fuel dilution in oil.

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Something that we must remember is, this are HYBRID vehicles by concept ( ICE plus electrical assist) and never meant to be used as electric motive power.
Now, after few years of using a "Modified" to EV vehicle, we are finding the consequences.
Mine, so far is the added weight killing the rear shocks/springs and riding low.....

 

That's quite a vague statement, spanning 13 years of modifications. What's the difference between ICE and EV assist? 49%?

With the PHV offering a capacity much smaller than the aftermarket upgrades as well as software specifically designed to monitor & maintain good vehicle health, the need for caution will be much lower. PZEV emission-rating certification will pretty much guarantee hot enough operating temperature anyway.

We appreciate what those of you who are driving augments now are doing to help with plug-in advancement.
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There will be a forced maintenance cycle, where the engine will be run regardless of EV availability.

Traditional vehicles actually have the same problem. If you only live a few miles from work, the engine simply can't generate enough heat in time. That's really hard on the emission system, since contaminents like water cannot be purged that quickly.

It's actually one of the odd benefits of having a top EV speed of 100 km/h (62.1 MPH). Beyond that speed, the engine joins in and gets the opportunity to purge.
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For a while now I have been thinking that the Prius is an excellent platform for a PHEV but a poor platform for an EV. I have started thinking this way because of the problems getting in the ICE to get up to temperature and the difficulty in holding an operating temperature.

I think I am OK in my usage but I can see that pushing the EV usage more than what I do will cause more issues and more risk.

So Let me describe my typical usage and ask for opinions from those of you that have more experience than I have about the effects of running with a cold ICE.

I drive on average about a 35miles round trip with a stop or two of 1-2 hours off time in the middle. I do 55mph for 3 miles toward the beginning and 3 miles toward the end. Most of the rest is slow enough to get EV. I have started using a EBH before the drive so I am starting at close to 100degF. I am getting about 40% of my trip above 155degF but that does not start until I the end of the 3 miles at 55mph at the beginning of my trip. Then it drops below 155degF while I am doing EV. On the way home in the last 3miles at 55mph I hit 180degF and stay above that for about 5 minutes.

So the real question is if this last 5 minutes above 180degF is enough to keep my oil in good shape?

Thanks,
Dan

 

Part of the problem is Toyota does not want these kits, so they do not allow software to control the drive train for a phev. The kits take advantage of a hack, which fools the system and does not run the engine properly. We can assume that when these are made commercial the car companies will program their cars to work better in regards to engine warm ups. GM does a forced run based on the calendar, and who knows, part of the operation problems might be aided by premium gas. Note premium runs cooler but may help with problems with stale gas. I'm sure toyota with their years of testing is looking into the fuel and lubrication system of phevs.

I have a gen III, but initially thought I might buy a kit when I bought my car. I wonder if the kit makers know what's going on and can modify their software to help with this problem.

 

Should be. But then again, how long would that scenario go unbroken? Never traveling beyond the time & distance is possible, though unlikely. And it's pretty much impossible during the warm season since warm-up is so much faster; you're not drawing heat from the coolant then either.

Wouldn't changing the oil once per year easily cover that, especially if you did that just prior to the cold season starting?
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Hi John,
I am not sure that understand your comment correctly.

I do on occasion do a trip of several hundred miles and during that time the Prius just runs in normal hybrid mode. That is not my concern. The question is if the ICE has wear or damage if I only do my routine day in and day out for say 3 months. Or worse, what would happen if I find some way to further improve my EV like a bigger battery pack or installing a temperature hack.

By the way I do Max Grill Blocking but I do not do the Temperature hack.

Also I am not sure that the beginning of the cold season would be the right time to change the oil. That would mean that I would do the worst Oil contamination right after the oil change and then drive with that oil during the rest of the year.

Thanks,
Dan

 

How is that any doesn't different from what some no-plug owners do already?

The recommendation would likely be to follow a "harsh condition" schedule then.
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Both I and TheForce are clearly different than the no-plug users. No-plug users will get to 155degF in 3 miles or less and stay above the temp for the rest of their drive. I am below 155degF more than 1/2 the time. I am guessing that TheForce is even worse than I am for ICE heating.

But the real point here is that TheForce has what most of us would conceder as an unacceptable oil analysis. The question is how much Plug-in assist is OK before we need to worry about problems from a cold ICE.

I expect that I might get a comment like follow the "harsh condition" schedule from a Toyota dealership. But if I did, I would never go back to that dealership. I would conceder this advice is an uniformed guess. I have much higher expectations of some of the most knowledgeable people that post on PriusChat.

I guess that what I am really looking for is some technical information on what temperature profile is needed to keep the oil in good condition.

Thanks,
Dan

 

Running 0W-20 in itself is different, since 5W-30 is the norm for the Iconic model. Do we have a basis of comparison available? The next analysis at half the usage (5K total) should be quite informative.
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Thanks for posting this. I've got the Hymotion unit as well but with the hills around my house and the freeway driving I have to do I probably don't have to worry about this much...you might have just saved me the money I was thinking of spending on an EV switch. Who does your oil analysis?

 

Man, u guys just have all the "theories" don't you. Let's just wait till force do a second oil analysis under standard hybrid condition.

Force. I noticed that u have 0-20 oil would u consider the standard Toyota recommendation just for this experiment?

BTW. Thanks for sharing your experience. I was tempted to do a 15k oil change interval. I might just put couple oil analysis along the way.

 

I was going to wait until 10K because of the Hymotion kit, but I'll change the oil at about 8500 miles. I was wondering if getting the TBN test for the additional $10 was worth it.

Also, I thought at one point PriusChat had worked out a group rate with Blackstone. Is that still going on?

 

Have changed my (12KWh PIS conversion) driving habits a bit since understanding this issue. So I am starting in hybrid mode, and only using pure EV after fluids are warm. I still can achieve > 80mpg on my hilly highway commute.

So with the ScanGuageII, what are the best temperature parameters to monitor? So that I can accurately determine when I can cut the ICE.

 

If I start in full EV mode for short distances I don't mind but I engage my PHEV for long term driving/commute after reaching 145 deg., the engine spins and makes everything happy.

 

Understand, but could you list the ScanguageII parameter you are useing, inverter temp?

S

 

Sorry, I'm NOT using scangauge of any sort, CANVIEW products are my thing on a large 7"display among a myriad of other parameters at the same time.