jungleX

What negative long term impact is there, if any, by using petrol blended with 10% ethanol?

ggebhardt

it it is a waste. No need for alcohol which has less energy that gasoline. When we first started doing the ethanol thing the EPA blew up saying that the harm to the environment to grow this extra corn was way worst, but it died away.

There is not a really long term problem except ethanol's love for water and any tank full of this blend will have some water in the bottom of the tank. What worries me is they want to increase the ethanol to 15% or even 20% in the future. It just wasting horsepower. To me the ethanol is part of the global warming thing which is really just about money. The corn states have very strong lobbies that grease the palms of our politicians.

There is really no good reason or advantage to have ethanol in our gas except to fatten the corn growers pockets.

FastFord

I was ready to trade my 2016 RX F sport 3 for a 2017 450h F sport due to the poor performance of the transmission and my frustrating with the hesitation and jerky ride. Took a new 450 for a drive while they worked on a Canadian version TSB of the tranny issues. Apparently Lexus Canada has not done a transmission ECU change in Canada. See my post under https://www.clublexus.com/forums/rx-...ost-159-a.html

Anyway, I really enjoyed the 450 but after getting my 350 back with the tranny fixed....I don't think I will be selling my 2016 yet.

More fun to drive for me would be the 350 with a properly tuned tranny. The 450 was awesome but not enough to trade the 2016.

If I was in the market as a new buyer, 450 all the way. Dealer made me a deal I almost couldn't refuse. I would bet that dealers are giving better deals right now on 450's

Koetsu

Well, not quite. Below are the acceleration figures from Consumers Report. The mid range kick that we all notice for the 450h was measured, but the overall accelerations for the two are practically identical. First column lists the RX350 stats and the second column is for the RX450h.

RX350; RX450h

Acceleration (overall rating):

4/5; 4/5

0 to 30 MPH (sec.):

2.9; 3.2

0 to 60 MPH (sec.):

7.5; 7.5

45 to 65 MPH (sec.):

5.6; 4.3

Quarter-Mile (sec.):

15.8; 15.8

Quarter-Mile, (mph):

92; 95

Apologize for the deviation from the thread topic, but there was a misconception stated that would be desirable to have rectified.

ericsan13

It does seem odd that the hybrid is only 0.3 seconds slower to 30mph, but is a whopping 1.3s faster from 45-65mph. If this is the case how can the hybrid be that much slower from 30-45mph?

Assuming 0-60 is correct and 75% of the time of the 45-65mph times is needed for 45-60mph, this would mean:
450h: 3.2s (0-30mph) + 1.07s (30-45mph derived) + 3.23s (45-60mph) = 7.5s
350: 2.9s (0-30mph) + 0.42s (30-45mph derived) + 4.2s (45-60mph) = 7.5s
This doesn't make sense to me.

Here's two videos of a 450h non-sport against a 350 sport with the same amount of gas and similar mileage:
Both of them are way faster than the consumer reports test, which also makes the consumer reports test suspect. You could also argue that the hybrid normally gets the eco tires which affects traction.

Anyway, if anyone wants to drag race, let's do it and get laughed off the street by just about any other luxury SUV out there. Oops, my apologies as well for going off topic.

Htony

If one needs to drive in snow. hybrid snow mode is not much help in deep snow. reason I traded it in for Audi SQ5 with Technik trim. (Prestige in U.S.) The feel of driving 450h is little different. Need to get used to it. One example is brake with the counter EMF assisted braking.
Brake pedal feels different at first. Living in North with cold winter months, had to watch state of 12V battery.

Koetsu

Not about to stoutly defend CR, but I suspect that they did the acceleration tests in Normal mode and with regular 87 octane gasoline for the RX350 and premium (91 octane?) for the RX450h. The mid range 'kick' for the 450h at about 35 mph is consistent with what I recall for test driving more than one hybrid RX from the 3rd and 4th generations. I obtain a qualitatively more lively response than they do with my RX350 in Sport mode and with premium fuel, which would agree with your video. Not proposing drag races, however, their (CR's) results do tend to dispel the notion that one version of the 4 gen RX is significantly faster than the other. The transmissions in both vehicles in your tests appear to have functioned just fine and as intended.

JSracer

on a 16 or 17rx ??
looking but not seeing any information, although you make this statement a few times a week.
to think this vehicle is as capable as the LX or GX or any other 4x4 in deep snow is crazy..

i live in minnesota, and ordered a 17 rx450, no concern here.

ericsan13

The hybrid would be at a disadvantage here. If the car came from Lexus for testing, it is highly likely that both cars came with 87 octane. It takes several tanks for the RX to adjust timings once you start putting in minimum 91 octane gas for the hybrid. Since the 350 is designed for 87 and the hybrid is designed for 91, it would put the hybrid at a disadvantage. It's a hot topic, but most folks do not believe putting in 91 into a car that requires 87 has any benefit whatsoever. But good call-out that gas would affect the results as well. Even the options added can add weight.

We really would have to drag race these cars (legally) to know.

ericsan13

How deep of snow are you talking about? Not that I do it often, but I got my non-VDIM 350 stuck in 6" of snow but my hybrid had no problem. My hybrid drove beautifully over the snow covered mountain passes. There is no hybrid snow mode by the way, that might have been the last generation model.

SQ5 is a sweet car, that's what I would've gotten if I didn't need the extra space.

Koetsu

Consumer Union always purchases its test cars (incognito, if possible) so their test samples were purchased through a dealer as would an individual customer. CR being CR, they tested each vehicle with the manufacturer's specified fuel grade. It is part of their usual protocol, as outlined in their publications. Their estimated annual fuel costs for the two are based upon regular for the RX350 and premium for the RX450h, hence the annual fuel costs are virtually identical (~$1500) for the two after mpg is factored into their calculation.

For what it is worth.

Freds430

What octane to use is probably the most heated debate on these forums. Do whatever makes you comfortable. I use 87 octane in our 2015 RX450h. Experimenting with the other two levels, I have noticed zero difference in gas mileage or performance. I have used 87 in cars that have required premium for well over a million miles and have not had one problem.
A previous post of mine on the subject.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4

From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.

Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.

Our 2015 RX 450h bought used two years ago was a $1,500 premium over the RX350's on the lot. Driving 15,000 miles a year and gas at $2.40 a gallon the difference in overall mileage between the two of 8 miles per gallon, the break even point on cost is three years. Added plus is quieter and more horsepower.

dtaylor

Looking to but my wife a new car. I see both 350 and 450 F Sport out there. I always buy used, with low miles, and both the 350 and 450 are out there. I predict she'll drive the next car 10 years, or more, plus I'll drive it to church on Sundays.

Looking for recommendations, opinions, experiences with both. Trying to educate before I buy.

Thank you in advance.

tempestv8

My humble opinion is that the F-Sport's firmer suspension (courtesy of firmer shock absorbers) is a little too stiff for my liking. With the RX450h being fairly leisurely on takeoff from standstill, the general mood for driving would be one of a more leisurely pace. So it almost seems a bit of an oxymoron to have an F-Sport RX450h.

I think an RX350 is more suitable as an "F-Sport" derivative, given the urgency of it's initial take off from standstill.

mssca

Personally I think RX 350 is a better buy if you are planning to keep it long term. But this is a personal preference because I don't know much about hybrid battery and motor reliability over 10 year lifespan. Some people say just like a mobile phone batteries, hybrid battery system will lose so much power that you will be driving around with basically more weight with no advantage to having that weight.