What Fuel For Rx400h?

[Mr Pants!]

I am after some advice from all the RX400h people out there.

I have always filled up my car with Shall v-power 99oct fuel. Ages ago I heard somewhere that all Jap cars perform better on 99oct fuel rather than the standard 95oct, better in fuel economy and acceleration.

Its almost like OCD that I have to now fill with Shell v-power and I sort of want to go back to 95oct, but feel like I am downgrading my car if I do this.

What are you thoughts on fuel, do you think stick with v-power or do you think there is nothing in it between these fuels?

Any feedback or advice would be gratefully received.

[Parthiban]

You can use either fuel, it won't cause any trouble. I use V Power mainly because I like that the engine sounds so much smoother, but I'm sure you'll find the majority of owners will run on 95 RON and won't have a single problem.

[ihpj]

Not sure the RX engine is tuned to run 'better' on the Super. I did some anecdotal testing on my RX and found little difference in anything other than engine note. By comparison our Aygo returns better MPG and increased efficiency on Super. But I can't bring myself to feed it that stuff regularly ;)

I would have thought the V6 3L would be better suited to Super than the 3CYL 1L engine of the Aygo.

[Vasos]

I think it won't be a prob.

V-Power in long term seems to achieve more miles for the same amount of gas, and have kind of "self cleanning" for the engine...

[Tazer]

I just did a 1500 mile trip to Europe and tried both to see the difference.

Driving at about 70 to 80 mph consistently (at night so it was possible!) I found that I got about 1 - 1.5 MPG improvement but I did not drive the same road twice using different fuels to compare exactly.

I also tried BP Ultimate vs supermarket 98RON fuels

The supermarket stuff had very little improvement over regular fuel ... make what you will of that!

[NickS]

I asked the salesperson a similar question when we bought our RX300, having found a slight benefit on our previous 530i BMW. He said there was no point, and I actually think that was good advice. However, I do occasionally fill one tank with V-power or equivalent, more to act as a cleaning agent. Must admit it seems to produce no identifiable improvement in mpg.

I recall "Which?" magazine tested higher performance fuel and additives, and only found a benefit for the better fuels in cars specifically stating they required it - I think some highly tuned Audi (RS models?) and VW, and doubtless other sporty models, specify higher RON fuels.

[Mr Pants!]

Thanks for the interesting replies.

Well I decided to go and do some accurate testing as I have used V Power for many many years and its almost an addiction that I feel I have to use v power only, which can be a pain when you are down to a quarter of a tank as you have to plan in where the nearest Shell is, I even flicked on the petrol station POIs on my sat nav.

So recently as my local Shell closed for refurb, I was forced to put in normal fuel 95RON and I decided to reset my MPG and see what happens.

I drive exactly the same route every day and drive the same way. I have not done long journeys or anything to give a false figure, nor have I changed anything, i.e. heated seat, load or aircon use. So this is a spot on representation of one persons use.

On V-Power 99RON fuel, I was consistantly getting between 29.8 - 30 MPG, I am not heavy footed with the throttle, but I do have a few hills, traffic and queues around and some areas where you need a bit of oomf to get out of junctions. Car performed well, I could not comment on the sound of the engine if it were smoother or not, its bloomin quiet and purrs as usual.

On normal 95RON fuel, Over a lot of mileage since posting this post in Feb, I am now consistantly getting 31.5 - 31.7 MPG which no matter how hard I tried I would never see with v-power on my routes, I feel no difference at all in performance or any change in smoothness of the engine. Plus I have the added bonus that I can fill up anywhere now!

So in summary, I think v-power makes no significant difference to the Lexus RX400h at all and is a waste of money, especially at todays fuel costs.

Keep in mind, I am very pro v-power as I definitely felt performance advantages when I used it in my Subaru STi and BMW Z3 M-Coupe which I used to own, so I believe there are models of cars that will benefit from the fuel but I would question if it is more efficient as I only got 18MPG in the STi, but that was a stupid car to own and run.

So there you go, that is my findings and I think there is a very fair and accurate representation for anyone out there who is considering it.

:)

[lexynik]

well written and informative information mr pants - very interesting

[ihpj]

I too was surprised that when trailing my RX on Super made no difference. However Super makes a real difference on the Aygo and my BMWs...one of those things I guess.