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Any Mods To Increas Mpgs On Rx400h


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I just read this article about the Prius getting 80-100 MPGs. The RX400h isn't much different so I'm wondering if anyone will create a mod for our cars. Wish I had some engineering experience to apply this to my RX400h:

http://www.autobeyours.com/HighSpeedStealth.htm

Yes, the mod is available, and is called trade-in :D

Sorry, I did not read the link. Thought you were talking about a new model.

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Can you imagine what the cost would be to replace all of those batteries? Also, what are the chances that a little-used engine will not succumb to oil sludge if its oil is not changed every thousand miles or so?

I think I'll pass on that mod!

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I just read this article about the Prius getting 80-100 MPGs. The RX400h isn't much different so I'm wondering if anyone will create a mod for our cars. Wish I had some engineering experience to apply this to my RX400h:

http://www.autobeyours.com/HighSpeedStealth.htm

Hi wildta,

First, saying "the rx400h isn't much different" is true, ONLY as applied to the basics of the HSD. Other than that the SUV version is VERY different from the Prius. The Prius was deliberatly made as light as practical, and it's low drag / shape was deliberatly made to defeat wind resistance. Not so, with the SUV. In comparison, it's a slug ... much heaver, and more drag, and 'over-powered' because it's market is to a buyer that expects more power. I too, wish Lexus' luxury RX sought to economize ... but you and I are in the minority.

Then there's hacking into the HSD's hardware. The 400h's ECU's control how much electric power is managed / used / cooled / charged / discharged. The folks who do this, really have to know what they're doing. Done in a slipshod manner, it'll take you into the realm of irreversable trouble codes ... and at that junction, you can kiss your warranty good bye.

That said, it HAS been done before. Dr. Andy Frank (U.C. Davis Prof) was one of the grand fathers of the plug in hybrid, and one of his first vehicles (that he had his students do) was a mongo Suburban sized land barge. And YES, it was averaging over 100mpg. But the whole 100mpg is kind of slippery. Sure, if you drive X amount of miles EV versus ICE, then you'll get 100mpg. But if you seldom recharge, your mpg may actually be WORSE than a standard vehicle. One of my favorite quotes of Dr. Frank: "This whole 'drill, baby, drill' thing is b*llsh*t"

BTW, using synthetic oil, these early conversions (done over 9 years ago now, in some cases) have suffered NO discernable acidic / sludgy wear ... much less the later ones being done by commercial companies. Some have logged over 100K miles, along the way, doing stints from 20 to 40 pure EV miles. There's some pretty cool mod's going on. But for SUV hybrids? None commercially, when it comes to PHEV's. A few conversions have been done on the smaller Ford SUV, the Escape ... but the mod is not offered for sale. I checked.

http://content.zdnet.com/2346-9595_22-18853.html

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  • 3 weeks later...
I just read this article about the Prius getting 80-100 MPGs. The RX400h isn't much different so I'm wondering if anyone will create a mod for our cars. Wish I had some engineering experience to apply this to my RX400h:

http://www.autobeyours.com/HighSpeedStealth.htm

Hi wildta,

First, saying "the rx400h isn't much different" is true, ONLY as applied to the basics of the HSD. Other than that the SUV version is VERY different from the Prius. The Prius was deliberatly made as light as practical, and it's low drag / shape was deliberatly made to defeat wind resistance. Not so, with the SUV. In comparison, it's a slug ... much heaver, and more drag, and 'over-powered' because it's market is to a buyer that expects more power. I too, wish Lexus' luxury RX sought to economize ... but you and I are in the minority.

Then there's hacking into the HSD's hardware. The 400h's ECU's control how much electric power is managed / used / cooled / charged / discharged. The folks who do this, really have to know what they're doing. Done in a slipshod manner, it'll take you into the realm of irreversable trouble codes ... and at that junction, you can kiss your warranty good bye.

That said, it HAS been done before. Dr. Andy Frank (U.C. Davis Prof) was one of the grand fathers of the plug in hybrid, and one of his first vehicles (that he had his students do) was a mongo Suburban sized land barge. And YES, it was averaging over 100mpg. But the whole 100mpg is kind of slippery. Sure, if you drive X amount of miles EV versus ICE, then you'll get 100mpg. But if you seldom recharge, your mpg may actually be WORSE than a standard vehicle. One of my favorite quotes of Dr. Frank: "This whole 'drill, baby, drill' thing is b*llsh*t"

BTW, using synthetic oil, these early conversions (done over 9 years ago now, in some cases) have suffered NO discernable acidic / sludgy wear ... much less the later ones being done by commercial companies. Some have logged over 100K miles, along the way, doing stints from 20 to 40 pure EV miles. There's some pretty cool mod's going on. But for SUV hybrids? None commercially, when it comes to PHEV's. A few conversions have been done on the smaller Ford SUV, the Escape ... but the mod is not offered for sale. I checked.

http://content.zdnet.com/2346-9595_22-18853.html

Highly appreciate your discussion. Very informative!

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BTW, using synthetic oil, these early conversions (done over 9 years ago now, in some cases) have suffered NO discernable acidic / sludgy wear ... much less the later ones being done by commercial companies. Some have logged over 100K miles, along the way, doing stints from 20 to 40 pure EV miles. There's some pretty cool mod's going on. But for SUV hybrids? None commercially, when it comes to PHEV's. A few conversions have been done on the smaller Ford SUV, the Escape ... but the mod is not offered for sale. I checked.

Based upon hundreds of oil analysis reports over the many years that GM has been filling its Corvettes with synthetic oil, it is common knowlege that anyone who runs an ICE for less than 5 miles on a regular basis will end up with excessive moisture contamination in their oil. While it may be true that sludge will not form as easily as it would in non-synthetic oil, the moisture can easily harm other components over time. In fact, oil reports that I've seen do point out above-average water content in oil because it should not be there.

Until someone can show me proof that excessive moisture in engine oil is harmless, I will continue to advise against buying a hybrid that contain an ICE that runs only after 40 miles or so, UNLESS there is some other feature that effectively removes moisture from the engine oil. This should not be considered a trivial "challenge" as to my knowledge, there is no adequate solution out there.

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My understanding is moisture forms from blow by. The Atkinson engine's crank used in the prius only completes one revolution (instead of the usual 2) per 4 piston strokes, I've read this configuration is less suseptible to blowby/moisture. In addition, I use a block heater, even in the summer, which means my 1st 5 minutes of 'warmup' are pretty much already done. Anywho, there's even a rotary version of the atkinson engine (a second cousin to the wankel ICE used in Mazda). It too has higher efficiency / less emission issues:

http://white-smoke.wetpaint.com/page/2.+General+Description

I'm guessing the lower hp from atkinson type engines is compensated by the electric motors, and I think I also heard that Lexus too is going to use atkinson ICE in their hybrids. Anyone heard if that's the case for the 2010 RX hybrid?

Oh! never mind, I did my own homework and it looks like the 2010 is using an atkinson ICE.

http://autos.canada.com/news/story.html?id...dd-d302206d2fc7

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Some moisture certainly does come from blowby. I have a glass "catch can" in my Corvette and primarily during the Winter months, it will catch a mixture of water and oil, a majority being water. During the rest of the year, its content is comprised of mostly oil. I do think that air contained in the oil pan contains moisture, so changes in temperature will encourage that moisture to condense into the oil.

That rotary Atkinson engine sounds interesting. I've always been a fan of the Wankel, but not its parent vehicle's fuel mileage.

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