Gen F fuel consumption

Gen F fuel consumption

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Discussion

BartW

Original Poster:

1,693 posts

169 months

Tuesday 26th April 2016
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Hi,
This is not a tread about expectancy for the car to be economical.

Just want to make sure it is all ok.

I have finally been driving the car, and I took it abroad, so all sorts of driving have been checked, and experienced.
Worth noting, standard MY14 GenF with the stock speed limiter in place managed 268kmh (167mph). All of that comfortably in 6th gear. If it wasn't for the limiter, it would probably do 180mph, or more? So unlike someone saying a long time ago, gearing would not be an issue preventing greater speed than 170mph.

Back to my actual point. Very steady driving at around 80 - 85mph for over 100 miles would return 21mpg.
Driving at 100mph would return 16mpg. Driving at 130 - 160mph would return 14mpg (logically). We are talking average fuel consumptions over long distances.

The car has done 6k miles.

The reason I query the above is that I hear of people getting way better fuel economy when driving sensibly. 25mpg - 30mpg was not unheard of. The tyre pressures are by the book. One thing I did, was change the exhaust to a 3" catback system by Harrop. I also tried what every LSA owners is supposed to do, i.e. Adjust the bypass valve by the charger. What seems to be a dead easy task to do, I have never seen an increase in the boost pressure going above 59kpa (read on EDI). Was it not supposed to read up to 70kpa post adjustment? Is it likely that I did it wrong, and as a result at steady lower speeds the. Bypass valve never fully closes, and keeps sending charged air through, thus enriching the fuel mixture for no benefit?

Someone tell me Gen F will not get much better on fuel, and I am ok. Just confirm, please. My old VE would return up to 30mpg when I used to have it.

snowwolf

11,503 posts

175 months

Tuesday 26th April 2016
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Sounds pretty good Bart, when I first got my car I had the middle screen set on fuel and I remember it reading always reading a lot lower than my old vxr8 it wasn't long after I set it to read my tyre pressures and that's where it stayed, I can't give you any figures but next time I am off down to West Country I will turn it back on to fuel economy and see what it does, yours sounds pretty good and I would not be disappointed with what your getting, was your speed measured on the clocks in the car or via sat nav ?

BartW

Original Poster:

1,693 posts

169 months

Tuesday 26th April 2016
quotequote all
Hi Mick,
All readings taken from the car, rather than gps, so I suspect it could over read a tad.

Thanks for confirming mpg sounds about right. Clearly, it's the Supercharger that consumes all the extra fuel at any throttle amount, given that it charges extra air.

pah250

3,269 posts

155 months

Tuesday 26th April 2016
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Here are my experiences of my 2014 Gen-F, also completely stock (for now).

BartW said:
Worth noting, standard MY14 GenF with the stock speed limiter in place managed 268kmh (167mph).
I also noticed the speed limiter kick in at 167mph (on a private road of course). Yet the book says it's limited to 155mph.


BartW said:
All of that comfortably in 6th gear. If it wasn't for the limiter, it would probably do 180mph, or more? So unlike someone saying a long time ago, gearing would not be an issue preventing greater speed than 170mph.
Mine also had lots more to give. It got to 167mph quite quickly, and then the HUD read something along the lines of 167MPH, SPEED LIMITER ACTIVE and then the car seemed to take its own foot off the gas and just held a constant 167mph. I'd agree that it might reach into the 180's if the limiter were removed.


BartW said:
Back to my actual point. Very steady driving at around 80 - 85mph for over 100 miles would return 21mpg.
Driving at 100mph would return 16mpg. Driving at 130 - 160mph would return 14mpg (logically). We are talking average fuel consumptions over long distances.

The car has done 6k miles.

The reason I query the above is that I hear of people getting way better fuel economy when driving sensibly. 25mpg - 30mpg was not unheard of. The tyre pressures are by the book. One thing I did, was change the exhaust to a 3" catback system by Harrop.
What you are seeing is broadly inline with what I see too. I think there are a few reasons for this, one of which might be that the VE has longer gearing so cruises at motorway speeds with lower engine RPM compared to the Gen-F. Also, I suspect that the 1900 blower on the LSA probably needs to spin a little faster than comparable TVS2300 installations on LS3's, and so I imagine that the parasitic loss of power from spinning the charger is a little higher on the LSA (someone feel free to correct me on this??)


Because I'm sad, I started keeping track of my petrol and mileage by way of brimming the tank each time I filled up, then then recording the mileage, putting all the figures into a spread sheet etc. Sad sad sad sad, I know..... but...

I've noticed that when comparing the standard Gen-F to my previous heavily modded VE (LS3, Walkinshaw 2300 S/C and wild cam), the average MPG is broadly the same. However, the VE got noticeably better MPG on a gentle motorway run, but noticeably worse MPG when opening the taps and driving spiritedly.

As for the MPG as indicated by the trip computer, I simply disregard this...


BartW said:
Someone tell me Gen F will not get much better on fuel, and I am ok. Just confirm, please. My old VE would return up to 30mpg when I used to have it.
I think you're right, this is as good as it gets, and that's the way it is. I also saw 30mpg out of my first LS3 in it's stock form. I remember getting 420 miles out of a full tank one time. But with a charger and with the LSA, it's more like 300 miles to a tank tops, and often less...


It could be worse, it could be a stinking Diesel!!!

V8NHH

437 posts

220 months

Wednesday 27th April 2016
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You fuel economy is good, I'm 19/21 mpg a tank and I drive 88kms a day on motorway although here in oz its stop start a lot of time. I also go drags atleast once a month.
As for bypass after I adjusted it I saw 62 Kpa previously 58kpa (.5psi)
After my boost pulley and headers I see approx 13-14psi max.

ringram

14,700 posts

248 months

Wednesday 27th April 2016
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Not sure why this is a surprise, a cursory glance at typical BSFC figures will show you the ~30%+ lower efficiency of FI vs NA

Ive continuously discussed this dispite idiots stating FI is more fuel efficient over the years smile

Just enjoy the extra power for acceleration and pay the price!


BartW

Original Poster:

1,693 posts

169 months

Wednesday 27th April 2016
quotequote all
Hi chaps,
Thanks for replies.

I am not complaining about the fuel economy being bad. Just wanted to ensure it is supposed to be this. My previous experiences with engines going bang, and other problems have made me be more cautious about things.

Still not sure why my boost bypass valve adjustment has made no difference, but hey, as long as it drives well, and develops the power, I am happy smile


PS. I have found that MY14 featured cupholders in the rear seat base, whereas MY14.5 did not.


snowwolf

11,503 posts

175 months

Wednesday 27th April 2016
quotequote all
I have not looked at my bypass valve yet, I suppose I'm unlikely to touch it as it is running so well smile perhaps it was adjusted when WP fitted the cam etc ? mine has the rear cup holders, strange the slightly later one did not have them ?

pah250

3,269 posts

155 months

Wednesday 27th April 2016
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Mine also has the rear cup holders. It is the earliest car in the UK though - No. 001

snowwolf

11,503 posts

175 months

Wednesday 27th April 2016
quotequote all
1st one Paul !!!!
pah250 said:
Mine also has the rear cup holders. It is the earliest car in the UK though - No. 001

HappyMidget

6,788 posts

115 months

Thursday 28th April 2016
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Motorway I get about 300 miles per tank, urban 150-200. MY14 with boost solenoid adjusted and CAI. With limiter removed I got 167 at the mile last year at Thunder Road in 5th and it was still pulling.

BartW

Original Poster:

1,693 posts

169 months

Thursday 28th April 2016
quotequote all
Could anyone please take a picture of their selenoid, I would like to cross check it.

I am getting no more than 250miles to a tank on the motorway. All around 80 - 85mph. Higher speeds on motorway, and it goes down to 16mpg, and 14mpg if really pushed. This is in Germany, mind.

Magic919

14,126 posts

201 months

Thursday 28th April 2016
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Have you considered LPG?

ARAF

20,759 posts

223 months

Thursday 28th April 2016
quotequote all
BartW said:
I am getting no more than 250miles to a tank on the motorway. All around 80 - 85mph. Higher speeds on motorway, and it goes down to 16mpg, and 14mpg if really pushed. This is in Germany, mind.
That could very easily be down to driving style.

HappyMidget

6,788 posts

115 months

Thursday 28th April 2016
quotequote all
BartW said:
Could anyone please take a picture of their selenoid, I would like to cross check it.

I am getting no more than 250miles to a tank on the motorway. All around 80 - 85mph. Higher speeds on motorway, and it goes down to 16mpg, and 14mpg if really pushed. This is in Germany, mind.
Will do when I get back at the weekend.

ringram

14,700 posts

248 months

Thursday 28th April 2016
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Magic919 said:
Have you considered LPG?
Nice Joke. Like asking if he has considered AIDS.

His last LPG engine killed itself as they do.

smile

BartW

Original Poster:

1,693 posts

169 months

Thursday 28th April 2016
quotequote all
I would argue, whether my last engine shat itself due to lpg, but would not consider it on LSA. It's too complex with the charger, and no spare wheel well. Also, I have a works pickup and mileage I do in the GTS would mean I'd need 25k miles, or 5 yrs to break even in the first place. Not worth. It's not a commuter car.

All I want to ensure is that the fuel consumption is normal for what it is.

PS. Will be much obliged for the pic.

ringram

14,700 posts

248 months

Thursday 28th April 2016
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Should have bought an LSA maloo for work smile
Its not too late!

Kevros

47 posts

108 months

Friday 29th April 2016
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With the cruise control on and set to 70 mph my car averages about 22 mpg on the motorway. And around town about 15 to 18 mpg GenF GTS only modification is the bypass valve readjusted

Edited by Kevros on Friday 29th April 11:55

ringram

14,700 posts

248 months

Friday 29th April 2016
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Good to see the GTS selling nicely in any case.
Fuel prices will help get a few more over here than you would normally expect, which should help the parts scene.
I wonder how the ute sales are going? I imagine a reasonable number are on the way/here.