Favourite 'Lude fuel?

bb1boy · Post by **bb1boy** » Thu Mar 28, 2013 1:41 pm

Hey all,

I've done a quick search but can't seem to find anything much on this topic.

Maybe a poll would be a good idea, because I would like to know what fuel you all run. Brand and octane rating.

I believe our JDM car's are tuned to run 100 octane fuel, whereas UK spec cars are set up for 95-98. Is this correct?

Personally I ONLY use super unleaded petrol (apart from when I'm running LPG) and use Tesco Momentum99 over Shell V-Power because to me they feel the same but the M99 is on average (in my locality) 8 pence cheaper per litre.

Also, I know the myths about octane booster petrol additives so my next question is, how hard is it to convert our motors to run Nitromethane instead of gasoline? I added a cup full of nitro fuel to about a quarter tank of petrol in my old 'Lude and I'm sure it improved performance, altho this could probably be put down to the placebo effect - like putting a universal (sound enhancing) cone filter on a stock 1litre Corsa.

Post by **Merlin** » Thu Mar 28, 2013 1:48 pm

I only ever put 95 RON (often supermarket) fuel in my UK 5th gen (H22a8) and it has always made the power it should do while on the dyno. Personally, for my 5th, I class anything better then 95 a waste of cash as I wont get more, or noticeably more, power from it.

I think the term for stock JDM's is a minimum of 97 RON.

Post by **Pushki** » Thu Mar 28, 2013 1:51 pm

Tesco Momentum99

Post by **ddoubledanny** » Thu Mar 28, 2013 2:00 pm

V power

judderod · Post by **judderod** » Thu Mar 28, 2013 2:08 pm

I'm sure that difference in fuel for JDM means a slightly more advanced timing on their ECU's, which explains why they had a slightly higher stock BHP rating.

I've only ever used shell v power on my built motor. But that's because it's tuned for it. Anything else is risky since it could knock. All I'd need to do is take 2 degrees off the whole igntion map, but where's the fun in that.

Octane boosters are a waste of time unless you advance the timing to make use of the added knock resistance. Oxygenators however do increase power, and these might be what's also contained in stuff labelled octane boosters (since no one would buy it otherwise).

IIRC, shell v power has the highest levels of oxygenators, as well as the highest level of knock resistance of any road fuel. All well and good but it's a fair bit more expensive, so I only buy it because it's running in an engine tuned to actually make use of all that added chemical soupery doopery business.

For my other car, I just use whatever gets the best mileage. I find it varies, but if shell fuelsave is no more than 2p dearer than the cheapest unleaded, it's worth getting since I get about 30 more miles out of the tank (I drive like a proper granny in that car)!

Post by **Merlin** » Thu Mar 28, 2013 2:08 pm

My track cars new engine/ECU is mapped for VPower only. For that engine it was explaned to me like this:

VPower - yup all good
Momentum99 - It will work but not as good
97 RON - only to get you home, no hard driving
95 RON - Its use = boom!

The problem is I dont have any Shell garages that are convenitent to use so I am getting a couple of 20L gerry cans

Post by **si import** » Thu Mar 28, 2013 2:33 pm

I use momentum99 mainly because theres not a shell garage close by.

Post by **RattyMcClelland** » Thu Mar 28, 2013 3:02 pm

Tesco only ever have 99 on certain pumps. V power is way more excessable and more stations around me.

chrismc · Post by **chrismc** » Thu Mar 28, 2013 3:10 pm

When I had my old Golf mapped on DTA by Track n Road they told me they had previously experimented with different fuels, back-to-back runs, drained tank in between & the only thing that altered power (albeit only slightly) was using some special octane booster from a 40 gallon drum (at huge cost).

The everyday pump fuels whether 95 or 98 octane produced less than 1% variation.

The 'better' fuels protect against knock slightly better so might allow a degree or two more ignition advance. If a car is mapped aggressively on 98 I'd stick to what it was mapped on.

However, on a car using a stock ECU no point using anything other than 95 unleaded IMO

Dbo · Post by **Dbo** » Thu Mar 28, 2013 3:48 pm

we have discussed this one before

Shell V-Power is the only true 99ron in the country, it is the only one i will use

Tesco get their fuel direct from BP and the 99 is not 99

it is 97 with an additive and is quite hit and miss with the mix each time

it has been sited in many court cases against Tesco! i used to work there and even the staff with high end cars wont use it

so if you run UKDM use any but if its JDM V-Power only