RCF Eco Mode Works?!?!

[Jgtcracer]

On a recent trip down south I managed a respectable 33mpg cruising down the A1 at 70mph.  I did this in Eco mode thinking this is what it’s designed for. It 100% made a difference.

I have previously had a suspicion that it does indeed improve my MPG a bit and have out this down to gearbox behaviour and throttle response.  The spoiler also stays down up to around 90mph, do we think this contributes also?

 I’m increasingly using Eco on my commute as the character of the car changes and everything calms down, good for listening to podcasts!

Looking at my driving style and the country roads I’m driving, I feel the principle reason I’m seeing an increase is because of the gearbox being more willing to shift up.  I was typically getting around 23.5mpg but am now seeing around 25.5mpg. 

Personally, I don’t feel the RCF is a car that people should be counting the MPG in, it’s never going to be ‘good’ but if you can have some free on a routine drive, why not!

I tend to do my spirited driving in sport as the paddles tend to do exactly what I want, find in sport+ it sometimes hangs into gears when I want to shift down etc.  Wish you could configure the piped in noise to be on permanently though!

 Replacement airbox it is I guess!!

 Marcus

[hockeyedwards]

I never use full Eco mode and by that I mean, using the toggle to switch from normal to Eco, I do however have Eco icon that pops up when driving a certain way in Normal mode.

The Full Eco mode did my head in, naff throttle response and lack of willingness to kick down got on my nerves. Even on long cruises I just keep it in normal and stick cruise control on. My day to day driving I get about 24mpg. Had 36 mpg after being stuck in a 50 zone for what seemed like forever. Generally get about 33-34 at national speed limit.

I drive in Normal Auto and Sport S in manual, prefer the gearbox and steering behaviour. Sport S+ is good when you know the road is gonna be empty. Few early morning blasts down to Goodwood have been epic, TVD can be awoken!

You could be cheeky and remove the vacuum line to the OEM airbox and it'll keep the flap open permanently so you get more noise from the get go. With aftermarket exhaust on, I have the ASC off all the time (although I think it's only actually active in the two Sport modes).

[Spock66]

2 hours ago, Jgtcracer said:

The spoiler also stays down up to around 90mph, do we think this contributes also?

In theory yes as the purpose of the spoiler is to create down-force for more grip when cornering, on the straight it will just increase drag and hence use more fuel (just like DRS in Formula 1), but how much difference in practice that makes who knows.

[ColinBarber]

Some cause and effect in action here. Eco is more economical because it dulls everything down and you therefore accelerate and drive slower - most savings could be achieved in normal mode. I'm not actually sure the gearshift pattern is changed in Eco, the technical manual doesn't state this, only the throttle is changed, which then causes the shifting to be different. The aircon is altered though, it cuts in and out more in eco mode to save fuel.

Technically you can accelerate more efficiently in manual mode as the torque converter is locked up in gear 2 through 8, whereas in auto you only get flex lock up from gear 4 onwards and full lock in gear 5+. But you would need to be very disciplined not to have some fun.

 

1 hour ago, hockeyedwards said:

I do however have Eco icon that pops up when driving a certain way in Normal mode.

That indicates the engine has switched in to an Atkinson cycle to be more efficient when cruising. There is a setting to stop the indicator illuminating, but it still actually happens if you turn it off.

 

3 hours ago, Jgtcracer said:

The spoiler also stays down up to around 90mph, do we think this contributes also?

I'm sure it must do for Lexus to make the change between modes - but cannot find any details on how much.

[hockeyedwards]

Very interesting re the Eco icon, I had seen you could turn it off but was quite happy for it be active in Normal mode if the conditions demand it. Funny how turning it 'off' doesn't actually do anything.

[NemesisUK]

Does the appearance of the Eco icon signify the engine has switched from the Otto cycle to using the Atkinson cycle?

https://mag.lexus.co.uk/atkinson-cycle-engine-work/

[TG1]

3 hours ago, hockeyedwards said:

You could be cheeky and remove the vacuum line to the OEM airbox and it'll keep the flap open permanently so you get more noise from the get go

I've heard of people doing this and am wanting to try it but just worried if there are any long term impacts to the car from doing this. 

The flap opens anyway after about 3200ish and sits open when the car is off so I am guessing there would be no downside other than maybe some heat soak?

Are there any known issues with capping the vacuum line other than heat soak? I am guessing some people have had the flap open for years by now, especially some of the ISF guys.

[hockeyedwards]

I am yet to read anything regarding long term problems. As you have mentioned the only thing that was considered was heat soak, but unless you were chasing some gainzzz I doubt it matters that much.

Once you get an aftermarket exhaust, it probably won't matter!

[dman2004]

3 hours ago, TG1 said:

I've heard of people doing this and am wanting to try it but just worried if there are any long term impacts to the car from doing this. 

The flap opens anyway after about 3200ish and sits open when the car is off so I am guessing there would be no downside other than maybe some heat soak?

Are there any known issues with capping the vacuum line other than heat soak? I am guessing some people have had the flap open for years by now, especially some of the ISF guys.

Haven't heard of any long term problems, however it does drink A LOT more fuel - maybe it's me, my heavy right foot hearing the intake at 1800 rpm. It does make the intake very bass'y, certainly turns heads if you give it some beans.

[ubersonic]

6 hours ago, TG1 said:

I've heard of people doing this and am wanting to try it but just worried if there are any long term impacts to the car from doing this. 

No problems, well other than a slight reduction in power/acceleration but we're talking so negligible you'd never feel it, only something you'd notice on drag strip printouts.

It's been done by many ISF owners over the years and many Honda Prelude owners (same airbox design), it's essentially a free noise upgrade.

[TG1]

Thanks guys I'll order some vacuum caps and give it a go

[MNMJ]

If this is what you mean, then I've had no problems in 5 years of running. I now use a black golf tee instead of a pencil. 

 

When Richard Meaden was running an RC-F long termer for EVO, I sent the suggestion to him. He did the same to his car, saying it was a worthwhile mod.