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Posted

To all of those RX400h Owners out there:

Lexus posted ten tips for improving the RX400h fuel economy...

http://www.lexus.com/assets/models/hybrid/...mance_guide.pdf

Out of all of the ten tips, what was most interesting to me was:

"9) Use premium fuel to improve fuel economy and performance"

Ever since other owners on this site have been advocating using regular fuel, I've followed the crowd, with obvious ramifications (10% reduction relative to super unleaded). I did, seemingly notice slightly lower performance and lower fuel economy (24 mpg to 22 mpg).

Just wondering - anybody else observing the same?

Cheers,

Peter

Posted

Wow, I didn't know my 400h was that much faster than the Porsche Cayenne S.

This is a great flyer for those wondering why their not getting 31 mpg city. The govt test these cars on a flat road, with no AC on, with light acceleration. Most of us drive our cars on slightly hilly roads, with the AC on, and under heavy acceleration.

Thanks for the link.

Posted

To me it didnt make sense to use anything but regular fuel, however on my last tank i went for the midgrade 89 octane and i do notice improved fuel economy. Freeway driving at around 60 mph with cruise when possible and no AC (its cool in Seattle), then flat side roads at 40 gave me an even 30 mpg on a sixty mile trip. I have another 40 miles on this tank of incity shorter driving and i am at 28 mpg right now. I'll have to see how the rest of the tank goes. This is about a 2 mpg improvement over regular gas.

Posted

It's basically a wash - with superunleaded running almost 10% higher in cost than regular, any fuel savings because of better mileage is used up as added fuel cost. The minor benefit is extra power, but let's face it, few of us are asking for MORE power!

Posted

I've noticed improved fuel economy with premium fuel for a long time. I would get about 1-2 MPG better on my 1999 RX 300 and performance noticeably improved with premium. I stopped using regular unleaded period.. I've not bothered even trying regular on the 400h.

Katjamr's experience is quite telling and I've personally confirmed that running with no AC makes a huge difference. I'm right at 3200 miles on my 400h. For the last 1000 miles, my overall average is 26.9 MPG. But, the last 200 has been largely without the AC (usually with the windows open -- which also probably hurst economy due to reduced aerodynamics). In the last 200 miles, I've estimated that I've averaged around 29 MPG. So, with AC, I get around 26.4 or so and without AC (with windows open) I get around 29 MPG. All of this is a daily commute of 30-40 minutes each way on a roughly 50/50 mix of hwy and surface streets (with some bad traffic thrown in on the hwy).

My experience is that the RX 400h's EPA numbers are not overstated at all. The AC accounts for a huge reduction.

Now, I wonder if the heater will reduce fuel economy in the winter?

Posted

I have been filling up my car with regular. It seems to run great. Acceleration is more than I need, but--I'm getting about 24 mpg. Now, I haven't been trying to get wonderful mileage, just driving it to suit my needs which means air on, short trips of mile, faster start up, etc. Now the thought occurred to me that even thougn the price of gas is prohibitive (middle grade would be about 10 cents and premium 20 cents more per gallon) if I got 2 miles more per gallon I'd actually be ahead because the price of gas is so high! Of course, if the mileage isn't better I'd just be wasting my money. Any thoughts?

Posted
I have been filling up my car with regular. It seems to run great. Acceleration is more than I need, but--I'm getting about 24 mpg. Now, I haven't been trying to get wonderful mileage, just driving it to suit my needs which means air on, short trips of mile, faster start up, etc. Now the thought occurred to me that even thougn the price of gas is prohibitive (middle grade would be about 10 cents and premium 20 cents more per gallon) if I got 2 miles more per gallon I'd actually be ahead because the price of gas is so high! Of course, if the mileage isn't better I'd just be wasting my money. Any thoughts?

That is interesting, premium fuel. I did learn that on my RX330, the cars acceleration was better after two tankfuls or premium. The service manager said it took two tankfuls for the computer to set the performance.

I did get better mileage on my first tank of "dealer" gas. So after 6 weeks of regular, I have just filled up with premium. I will see if it makes any difference this week, made a difference in my pocket though...

Posted

Dear Forum Viewers:

Wow. So, following the performance guide, applying "feather like" acceleration and braking, no A/C, but WITHOUT the premium gasoline, I was able to achieve a ridiculous 37MPG (yes 37MPG) on a mix of highway and city driving for a 100 mile interval.

However, this required a LOT of patience on my end, accelerating slowly onto the highway, driving on the right side, and watching others pass freely (while driving 65mph).

Well, I guess the theory works, but at what cost?

Cheers,

Peter

To all of those RX400h Owners out there:

Lexus posted ten tips for improving the RX400h fuel economy...

http://www.lexus.com/assets/models/hybrid/...mance_guide.pdf

Out of all of the ten tips, what was most interesting to me was:

"9) Use premium fuel to improve fuel economy and performance"

Ever since other owners on this site have been advocating using regular fuel, I've followed the crowd, with obvious ramifications (10% reduction relative to super unleaded). I did, seemingly notice slightly lower performance and lower fuel economy (24 mpg to 22 mpg).

Just wondering - anybody else observing the same?

Cheers,

Peter

Posted

It works at the cost of having a performance car and driving it like an antique! Do I have the patience for that??? Maybe when I retire. Then I wouldn't need this car. I could own a little car with no power! I'd also have to cook when it is 90+ degrees. Now did you remove your roof racks, too? Only kidding. It's good to know their solution works. I just attended their Taste of Perfection on Saturday. They ran races with competition. For fun, I drove one of their new RX400h to see what kind of mileage they were recording and try driving in a way I'd never subject my own car to. They had and average of 5 mpg. on the car I drove!

I was really impressed with the new IS though. I drove that to test for my son who is in AZ.

Posted
To all of those RX400h Owners out there:

Lexus posted ten tips for improving the RX400h fuel economy...

http://www.lexus.com/assets/models/hybrid/...mance_guide.pdf

Out of all of the ten tips, what was most interesting to me was:

"9) Use premium fuel to improve fuel economy and performance"

Ever since other owners on this site have been advocating using regular fuel, I've followed the crowd, with obvious ramifications (10% reduction relative to super unleaded). I did, seemingly notice slightly lower performance and lower fuel economy (24 mpg to 22 mpg).

Just wondering - anybody else observing the same?

Cheers,

Peter

Hi from the UK:)

I can't understand the problem.

My 400h is 3 weeks old and I aam averaging 35 Miles per UK gallon when driving like my granny at around 40-45 mph.

When I criused between 55 - 60 and towing a car trailer with a medium load for 70 miles I got 29.5 mpg UK. I can easily get 33 -34 mpg (uk) when driving normally, mixed highway and town ! Maybe it is the weather! It is Autmn here now and I use the cheapest unleaded petrol :)

I am very pleased with it and it accelerates like a rocket when required (not very often!)

BR.

Billy

Posted

Ok so i won some money playing blackjack and gas has actually gone down about ten cents a gallon in Seattle recently so long story even longer i went for Chevron premium after my last tank of midgrade. After 100 miles of mixed driving, no AC, my average has gone from 26/28 to 28/30 mpg. The wierd thing is, and im not imagining this, it seems to me when the ICE kicks in like it does for battery charging or acceleration needs it is LESS smooth. Not the jerking surging problem people report, just not as silky smooth a transition as it was with regular gas. I will do at least two tankfulls of premium to see if this settles down.

Posted
Ok so i won some money playing blackjack and gas has actually gone down about ten cents a gallon in Seattle recently so long story even longer i went for Chevron premium after my last tank of midgrade.  After 100 miles of mixed driving, no AC, my average has gone from 26/28 to 28/30 mpg.  The wierd thing is, and im not imagining this, it seems to me when the ICE kicks in like it does for battery charging or acceleration needs it is LESS smooth.  Not the jerking  surging problem people report, just not as silky smooth a transition as it was with regular gas.  I will do at least two tankfulls of premium to see if this settles down.

Having tried mid-grade in my last fill up I have noticed the same thing. First I am gaining a little over 1 mpg (which I believe when you factor in the increased cost of gas still may be a losing proposition), but I have noticed that the ICE starts are much more noticable. I agree that you are not imagining this. I will also try a second tank and see if it makes a difference, but the way I see it now, there is no compelling reason to use any higher grade than regular in the car.

Posted
To all of those RX400h Owners out there:

Lexus posted ten tips for improving the RX400h fuel economy...

http://www.lexus.com/assets/models/hybrid/...mance_guide.pdf

Out of all of the ten tips, what was most interesting to me was:

"9) Use premium fuel to improve fuel economy and performance"

Ever since other owners on this site have been advocating using regular fuel, I've followed the crowd, with obvious ramifications (10% reduction relative to super unleaded). I did, seemingly notice slightly lower performance and lower fuel economy (24 mpg to 22 mpg).

Just wondering - anybody else observing the same?

Cheers,

Peter

Hi from the UK:)

I can't understand the problem.

My 400h is 3 weeks old and I aam averaging 35 Miles per UK gallon when driving like my granny at around 40-45 mph.

When I criused between 55 - 60 and towing a car trailer with a medium load for 70 miles I got 29.5 mpg UK. I can easily get 33 -34 mpg (uk) when driving normally, mixed highway and town ! Maybe it is the weather! It is Autmn here now and I use the cheapest unleaded petrol :)

I am very pleased with it and it accelerates like a rocket when required (not very often!)

BR.

Billy

Update from the UK: My workplace is 11 miles away on a country road withh very light traffic in North Yorkshire, which varies a lot in uphill and down hill gradients. It is somewhat lower (ASL) than my home. Today I drove very carefully both ways averaging 30 mph from 20 thru 30 even occasional 40 mph.

The outward 11 miles gave an average of 52.1 MPG !!! :) But the return trip of 12 miles ( I had to call for petrol) reduced it to 40.5 and the maneuvefring/ reversing for 5 mins or so in parking in the gargae reduced it to 39.5 mpg(UK).

I am very pleased with that :)

BR.

Billy

Posted

Thanks Jashev, it helps to have someone confirm what i thot was happening. Today things seemed smoother even tho they were short trips and the ICE was cold. I'm hearing it may take two tankfulls to adjust to the premium.

Posted
To all of those RX400h Owners out there:

Lexus posted ten tips for improving the RX400h fuel economy...

http://www.lexus.com/assets/models/hybrid/...mance_guide.pdf

Out of all of the ten tips, what was most interesting to me was:

"9) Use premium fuel to improve fuel economy and performance"

Ever since other owners on this site have been advocating using regular fuel, I've followed the crowd, with obvious ramifications (10% reduction relative to super unleaded). I did, seemingly notice slightly lower performance and lower fuel economy (24 mpg to 22 mpg).

Just wondering - anybody else observing the same?

Cheers,

Peter

Hi from the UK:)

I can't understand the problem.

My 400h is 3 weeks old and I aam averaging 35 Miles per UK gallon when driving like my granny at around 40-45 mph.

When I criused between 55 - 60 and towing a car trailer with a medium load for 70 miles I got 29.5 mpg UK. I can easily get 33 -34 mpg (uk) when driving normally, mixed highway and town ! Maybe it is the weather! It is Autmn here now and I use the cheapest unleaded petrol :)

I am very pleased with it and it accelerates like a rocket when required (not very often!)

BR.

Billy

Update from the UK: My workplace is 11 miles away on a country road withh very light traffic in North Yorkshire, which varies a lot in uphill and down hill gradients. It is somewhat lower (ASL) than my home. Today I drove very carefully both ways averaging 30 mph from 20 thru 30 even occasional 40 mph.

The outward 11 miles gave an average of 52.1 MPG !!! :) But the return trip of 12 miles ( I had to call for petrol) reduced it to 40.5 and the maneuvefring/ reversing for 5 mins or so in parking in the gargae reduced it to 39.5 mpg(UK).

I am very pleased with that :)

BR.

Billy

I assume we are referring to Imperial Gallons here :) .

Posted
To all of those RX400h Owners out there:

Lexus posted ten tips for improving the RX400h fuel economy...

http://www.lexus.com/assets/models/hybrid/...mance_guide.pdf

Out of all of the ten tips, what was most interesting to me was:

"9) Use premium fuel to improve fuel economy and performance"

Ever since other owners on this site have been advocating using regular fuel, I've followed the crowd, with obvious ramifications (10% reduction relative to super unleaded). I did, seemingly notice slightly lower performance and lower fuel economy (24 mpg to 22 mpg).

Just wondering - anybody else observing the same?

Cheers,

Peter

Hi from the UK:)

I can't understand the problem.

My 400h is 3 weeks old and I aam averaging 35 Miles per UK gallon when driving like my granny at around 40-45 mph.

When I criused between 55 - 60 and towing a car trailer with a medium load for 70 miles I got 29.5 mpg UK. I can easily get 33 -34 mpg (uk) when driving normally, mixed highway and town ! Maybe it is the weather! It is Autmn here now and I use the cheapest unleaded petrol :)

I am very pleased with it and it accelerates like a rocket when required (not very often!)

BR.

Billy

Update from the UK: My workplace is 11 miles away on a country road withh very light traffic in North Yorkshire, which varies a lot in uphill and down hill gradients. It is somewhat lower (ASL) than my home. Today I drove very carefully both ways averaging 30 mph from 20 thru 30 even occasional 40 mph.

The outward 11 miles gave an average of 52.1 MPG !!! :) But the return trip of 12 miles ( I had to call for petrol) reduced it to 40.5 and the maneuvefring/ reversing for 5 mins or so in parking in the gargae reduced it to 39.5 mpg(UK).

I am very pleased with that :)

BR.

Billy

I assume we are referring to Imperial Gallons here :) .

Yes. You need to divide by 1.2 i guess. But for me that is excellent although you guys seem to get better results over there...


Posted

Dear Forum Readers:

Coming back to this eternal question about the cost-effectiveness and other economic analysis of the RX400h, I think I personally made up my mind about it.

Lexus / Toyota could have probably made a hybrid SUV which generated consistently >40MPG real life mileage. But, the car would have probably enjoyed a 0-60 acceleration time of 10+ seconds, towing capacity of 1,000lbs, and other limitations which are represented in the competitive hybrid designs.

OH WAIT. Actually, I've been able to achieve 35-40MPG if I forced my RX400h to drive like a Prius. Or a Honda Insight. Or a Mercury Mariner. Or a Ford Escape for that matter. I just drive with "feather-lite" acceleration and braking, and get 10+ second 0-60.

BUT. By the slight depression of the pedal, I can achieve 650 ft-lbs of torque, comparable to a Chevy Corvette Z08 and compete with $70k+ super SUVs like the new Mercedes ML500, the BMW X5 4.8, and the venerable Porsche Cayenne S.

AND. The kicker for me is that at WORST, I've achieved 22 MPG. That was in the beginning. Lately, with a mix of optimized fuel economy driving and race car driving on the 101, my mileage has increased to 27MPG.

So was this an economically a sound purchase? 110%. There are no comparable vehicles out there that DON'T compromise on performance for gas mileage, while also providing the flexibility of maximizing fuel economy.

Another satisfied customer....

Peter

Dear Forum Viewers:

Wow. So, following the performance guide, applying "feather like" acceleration and braking, no A/C, but WITHOUT the premium gasoline, I was able to achieve a ridiculous 37MPG (yes 37MPG) on a mix of highway and city driving for a 100 mile interval.

However, this required a LOT of patience on my end, accelerating slowly onto the highway, driving on the right side, and watching others pass freely (while driving 65mph).

Well, I guess the theory works, but at what cost?

Cheers,

Peter

To all of those RX400h Owners out there:

Lexus posted ten tips for improving the RX400h fuel economy...

http://www.lexus.com/assets/models/hybrid/...mance_guide.pdf

Out of all of the ten tips, what was most interesting to me was:

"9) Use premium fuel to improve fuel economy and performance"

Ever since other owners on this site have been advocating using regular fuel, I've followed the crowd, with obvious ramifications (10% reduction relative to super unleaded). I did, seemingly notice slightly lower performance and lower fuel economy (24 mpg to 22 mpg).

Just wondering - anybody else observing the same?

Cheers,

Peter

Posted

Dear Forum Readers:

Coming back to this eternal question about the cost-effectiveness and other economic analysis of the RX400h, I think I personally made up my mind about it.

Lexus / Toyota could have probably made a hybrid SUV which generated consistently >40MPG real life mileage. But, the car would have probably enjoyed a 0-60 acceleration time of 10+ seconds, towing capacity of 1,000lbs, and other limitations which are represented in the competitive hybrid designs.

OH WAIT. Actually, I've been able to achieve 35-40MPG if I forced my RX400h to drive like a Prius. Or a Honda Insight. Or a Mercury Mariner. Or a Ford Escape for that matter. I just drive with "feather-lite" acceleration and braking, and get 10+ second 0-60.

BUT. By the slight depression of the pedal, I can achieve 650 ft-lbs of torque, comparable to a Chevy Corvette Z08 and compete with $70k+ super SUVs like the new Mercedes ML500, the BMW X5 4.8, and the venerable Porsche Cayenne S.

AND. The kicker for me is that at WORST, I've achieved 22 MPG. That was in the beginning. Lately, with a mix of optimized fuel economy driving and race car driving on the 101, my mileage has increased to 27MPG.

So was this an economically a sound purchase? 110%. There are no comparable vehicles out there that DON'T compromise on performance for gas mileage, while also providing the flexibility of maximizing fuel economy.

Another satisfied customer....

Peter

Yes, well said!

Posted

I have tried Premium and regular gas, I get better mileage with regular.

Could be me, but same roads times etc. Premium was 22.2, regular was 24.7-25.8.

I do notice some slight improvment in acceleration with premium, but only if it's flat out.

I tried this twice and used 2 tankfuls to make the test.

These are my findings with my car anyway.

Posted

Dear Forum Readers:

Coming back to this eternal question about the cost-effectiveness and other economic analysis of the RX400h, I think I personally made up my mind about it.

Lexus / Toyota could have probably made a hybrid SUV which generated consistently >40MPG real life mileage. But, the car would have probably enjoyed a 0-60 acceleration time of 10+ seconds, towing capacity of 1,000lbs, and other limitations which are represented in the competitive hybrid designs.

OH WAIT. Actually, I've been able to achieve 35-40MPG if I forced my RX400h to drive like a Prius. Or a Honda Insight. Or a Mercury Mariner. Or a Ford Escape for that matter. I just drive with "feather-lite" acceleration and braking, and get 10+ second 0-60.

BUT. By the slight depression of the pedal, I can achieve 650 ft-lbs of torque, comparable to a Chevy Corvette Z08 and compete with $70k+ super SUVs like the new Mercedes ML500, the BMW X5 4.8, and the venerable Porsche Cayenne S.

AND. The kicker for me is that at WORST, I've achieved 22 MPG. That was in the beginning. Lately, with a mix of optimized fuel economy driving and race car driving on the 101, my mileage has increased to 27MPG.

So was this an economically a sound purchase? 110%. There are no comparable vehicles out there that DON'T compromise on performance for gas mileage, while also providing the flexibility of maximizing fuel economy.

Another satisfied customer....

Peter

Yes, well said!

I have a great time puttering along when an X5 driver, shortly after noticing the "H" after the RX400, pulls into the left lane to blast by me. Not wanting to avoid "shock" therapy, I floor the gas pedal and rocket ahead. This happens every now and again and I still chuckle every time it does.....and we still average 25 MPG, heh, heh!

Posted

Speaking of this duality of fuel economy output on the RXh, perhaps it would have been a good idea for Lexus to place a button next to the shifter for the following modes:

E: Economy - Battery use maximized for ECONOMY, slow acceleration, etc. etc - MPG: 30+ (perhaps use the Prius algorithm for this one?)

P: Power - Battery use and gas use maximized for ACCELERATION - MPG: 15+

Oh wait, that button was also on my traded-in 99 RX. Why didn't they add this feature in the RX400h?

Cheers,

Peter

Dear Forum Readers:

Coming back to this eternal question about the cost-effectiveness and other economic analysis of the RX400h, I think I personally made up my mind about it.

Lexus / Toyota could have probably made a hybrid SUV which generated consistently >40MPG real life mileage. But, the car would have probably enjoyed a 0-60 acceleration time of 10+ seconds, towing capacity of 1,000lbs, and other limitations which are represented in the competitive hybrid designs.

OH WAIT. Actually, I've been able to achieve 35-40MPG if I forced my RX400h to drive like a Prius. Or a Honda Insight. Or a Mercury Mariner. Or a Ford Escape for that matter. I just drive with "feather-lite" acceleration and braking, and get 10+ second 0-60.

BUT. By the slight depression of the pedal, I can achieve 650 ft-lbs of torque, comparable to a Chevy Corvette Z08 and compete with $70k+ super SUVs like the new Mercedes ML500, the BMW X5 4.8, and the venerable Porsche Cayenne S.

AND. The kicker for me is that at WORST, I've achieved 22 MPG. That was in the beginning. Lately, with a mix of optimized fuel economy driving and race car driving on the 101, my mileage has increased to 27MPG.

So was this an economically a sound purchase? 110%. There are no comparable vehicles out there that DON'T compromise on performance for gas mileage, while also providing the flexibility of maximizing fuel economy.

Another satisfied customer....

Peter

Yes, well said!

I have a great time puttering along when an X5 driver, shortly after noticing the "H" after the RX400, pulls into the left lane to blast by me. Not wanting to avoid "shock" therapy, I floor the gas pedal and rocket ahead. This happens every now and again and I still chuckle every time it does.....and we still average 25 MPG, heh, heh!

Posted

I have 7700 miles on my RX400h and am averaging 27.06 mpg. I noticed a slight increase in mileage after 5000 miles. My last two round trips from Seattle to Portland have averaged 30.0 mpg.

I did run a couple of tanks of premium and I estimate a little over 1 mpg improvement, but did not notice any difference in performance.

Last night I attended a Lexus service clinic at my Lexus dealer. I asked about using synthetic oil. My dealer uses Castor Oil products. They have not used synthetic oil in any of their customer's 400hs. but think there could be a 1-2 mpg improvement due to less friction. I think they said that the synthetic oil costs almost triple, however.

So theoretically, you might see a 3-4 mpg improvement with premium fuel and synthetic oil. I haven't run the figures, but I don't think the numbers pencil.

Posted

Rex i always appreciate your posts, however i have a question about the oil info the Bellvue dealer gave you. I got my 400h from their sister dealership in Tacoma as the waiting list was much shorter. Their service people have told me on two occasions that the Castrol engine oil shipped from the factory and used in their oil changes is a synthetic blend. True its not 100% synthetic, however it does incorporate the best characteristics of both the dino oil and synthetic.

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