SpaceCoyote
Member
Siftah said:
It sounds interesting, although some of the power and MPG increases seem to good to be true
Unleaded vs Superunleaded
- Thread starter RichardG
- Start date
It sounds interesting, although some of the power and MPG increases seem to good to be true
SpaceCoyote said:
Yup, must admit I thought that too until I put normal stuff in the car on the way back from Scotland, worst MPG I've ever had from a tankful used on the motorway. I'll be covering a few thousand miles in the next week or so, so I'll be doing a bit more 'research'
i tend to find no increase in mpg with v-power,or any significant feel in increased power/response.
i do however feel the benefits when using either Tesco 99 or,what i use mainly is Pace/Q8 Super unld',so worth the extra for the added feel/response and aprox 2mpg gain
i do however feel the benefits when using either Tesco 99 or,what i use mainly is Pace/Q8 Super unld',so worth the extra for the added feel/response and aprox 2mpg gain
tomTVR said:
+1 agree with your statement .... plus you don't see the build up on your pistons if you use the regular on your car, only your Mechanic will see it and you end up paying the bill in the end. So using the higher octane as recommended by the manufacturer is the ticket
I have been using Shell V power / Tesco 99 on the last 10 fill ups and was getting around 260 - 275 miles out of the tank, same routes, same driving style.... I then accidently put in 95 one day... was really pissed off as I had been keeping to 97+ Ron in order for the DME to get used to the higher octane... anyway on this tank I got 305 miles out of it when I used to get 250 miles on 95. This makes me think the engine management has adjusted to 97-99 Ron fuel and when going back to 95 it somehow does more miles? I notice no difference in running or power between the 2, a cold day/hot day makes more of a difference IMO.
SpaceCoyote
Member
Filled up with Momentum 99 last night and I'm sure the car feels more eager and certainly smoother already. My last two tanks were Vpower and 97 RON super, so perhaps my ECU has already adjusted?
Could be wishful thinking though.
Could be wishful thinking though.
Beancounter1980
Active member
I started filling up on Super now.
The 3.0i definitely seems a bit more eager and not as "strained" as before. I'm sold..
The 3.0i definitely seems a bit more eager and not as "strained" as before. I'm sold..
SpaceCoyote
Member
Well after about 75 miles of Tesco 99, my MPG is 30.3 which is lower than with Vpower, although it is hard to get a true comparison since the town I travel through seems to have heavy roadworks and lots of temporary traffic lights which means I'm idling for at least 5 minutes each way.
Sticks said:
The hot cold thing may affect the economy but will have little affect on the power. I had my car dynoed (a couple times), the first was the most interesting in this respect. It was early this year and was around 4c. Did quite a few runs and the fueling varied a lot - between max threshold for leanness and richness (for an NA engine). The technician explained this was due to the difference between the warmer air in the garage and occasional blasts of cold air being sucked in by the fan. Interesting thing, even taking runs from both ends of the lean / rich spectrum, the power and torque curves were both almost identical.
I'd almost expect the car to do the same with the different fuels, adjust the running so the power stays the same, but increase the fuel efficiency - same size explosions from a smaller amount of fuel. Which follows what a lot of us have found - change to a higher octane improve fuel economy, in my 2.5 it pays for the difference
EDIT: PS, just putting on my flame proof suit!
Full details > sig > Dyno link.
PawnSacrifice said:I'd almost expect the car to do the same with the different fuels, adjust the running so the power stays the same, but increase the fuel efficiency - same size explosions from a smaller amount of fuel. Which follows what a lot of us have found - change to a higher octane improve fuel economy, in my 2.5 it pays for the difference
Thing is though Pawn, an optimum AFR for maximum power is tuned to 12.8:1 in NA form usually, however a Lean max torque would be around 13.1:1. Going to the lean side is less detrimental for power than the rich side but yields added danger of overheating the cylinders etc. You'll need high octane fuel to get to the lean side of this figure to get most power without the knock from the higher combustion temps. the 12.8->13.1 is already a few percent of fuel saving, however due to the efficiency from the delayed ignition timing also (igniting the fuel at its most optimal point), more fuel economy is netted also... Win win
After removing my spark plugs ~7k ago, you could really see the car runs a lean burn on Super Unleaded (whiteish brown) compared to normal (light brown). My previous VX's plugs were always black as it was aggressively cammed and ran like a bag of spanners :roll: :lol:
EdButler said:PawnSacrifice said:I'd almost expect the car to do the same with the different fuels, adjust the running so the power stays the same, but increase the fuel efficiency - same size explosions from a smaller amount of fuel. Which follows what a lot of us have found - change to a higher octane improve fuel economy, in my 2.5 it pays for the difference
Thing is though Pawn, an optimum AFR for maximum power is tuned to 12.8:1 in NA form usually, however a Lean max torque would be around 13.1:1. Going to the lean side is less detrimental for power than the rich side but yields added danger of overheating the cylinders etc. You'll need high octane fuel to get to the lean side of this figure to get most power without the knock from the higher combustion temps. the 12.8->13.1 is already a few percent of fuel saving, however due to the efficiency from the delayed ignition timing also (igniting the fuel at its most optimal point), more fuel economy is netted also... Win win
After removing my spark plugs ~7k ago, you could really see the car runs a lean burn on Super Unleaded (whiteish brown) compared to normal (light brown). My previous VX's plugs were always black as it was aggressively cammed and ran like a bag of spanners :roll: :lol:
Always be counted on for some solid info.