Which fuel to use?...

[Demons1964]

does anybody know anything about the fuel you can buy from the "United Servo's" called "United plus" its a 95 octain (I think) with ethonol... I've been told its amazing and about 2 cents cheaper than normal unleaded...

I think the 95 octane sold at United has 10% ethanol. The general guideline is that ethanol in pre-1986 cars is unacceptable. I worked out that using 50 litres per week, it equates to a saving of $50 over the full year. Not something I'm willing to take a chance on for the negligible cost saving.

 

[50 stevo]

the only reason people have trouble with ethanol in old cars is it mixes with water where fuel doesn't, so as long as you drop your tank and get rid of any moisture and make sure its sealed properly you should never have a problem as long as you don't let fuel sit in the tank for months without use. Getting back to premium unleaded, i ain't no expert but i was at the test track where i saw with my own eyes that premium had no great advantage over reg, infact they found changing from one brand of fuel filter to another made more difference than premium. So unless they wasted twenty grand on a test for nothing i would say they proved premium to be bullshit, not because 95 was better than 98, it was because unless you raise the octain level to 99.9 it makes bugger all difference . And on this test day it was the older stockers that got better results than the sports and performance models 50 cars tested

 

[VHSLX]

Plus ULP is the worst fuel , Go for the Optimax or if your feeling rich , fill up on BP Ultimate , Works wonders on my VH ,

 

[Goon]

I put unleaded prem in my VC the otherday with a nylon lead add and it seems to be running smoother then unlead with the add, but im still to try this optimax..

 

[synoptica]

To everyone saying that PULP is crap and a rort and that TT did a test to prove it:

1. PULP is crap in a car designed for 91 RON fuel. End of story.

2. PULP doesn't give better economy in a car designed to take 91 RON fuel. It gives more power in cars designed to harness it through it's slower, more controlled burn.

3. Today Tonight is the most biassed, bullshit, tell-the-public-what-they-want-to-hear-so-they'll-keep-our-ratings-up-but-really-we're-just-making-it-all-up show that there is on television.

Any Holden 6 is designed to run on the leaded fuel of its time - namely 97 RON Leaded. Unleaded is 91 RON. You can retard the timing at the cost of power (given they have none anyway you've not got much to lose). In this car, you will certainly get better economy because no doubt the thing will be pinging it's tits off half the time!

Another benefit of PULP is more consistent quality, smoother accelleration (quite possibly in all cars, not just ones designed to take higher RON fuel) and less carbon deposits. For my 4-6cpl more I think that's gotta be good value for money.

I notice no difference between PULP and Optimax in my VK. Going from LRP to PULP was the single biggest performance gain I've ever seen. After one tank the car felt so smooth on accelleration I'd thought it'd lost traction!

edit: ooh and I didn't like the Plus ULP either. Car didn't feel as nice on it. Though I am itching to try the Boost 98... like us revheads have known for years - alky fuels are GOOD!

 

[VX_KN079]

Take my cousins performance Ford Cobra 351 replica for example. If he runs on normal unleaded, the car would ping like crazy. He needs higher octane fuel and even then it pings a bit.

The problem isn't the fuel... It's the compression and timing. TRUST ME! I know this for a fact. If the compression and timing are tuned to the petrol, no matter what RON the petrol is, it will run like a dream.

 

[ausmaniac]

For all it's worth, I run my 202 VK on Shell '95 with Flash Lube drip fed into the intake manifold and there's no ping, plenty of go and better fuel economy.

 

[craigvk]

The problem isn't the fuel... It's the compression and timing. TRUST ME! I know this for a fact. If the compression and timing are tuned to the petrol, no matter what RON the petrol is, it will run like a dream.

If you know so much about it, maybe you can tell me why when he disconnects the vacuum advance, the car runs alright? :whistling

 

[WhiteLion85]

I have a question for all U VK nuts out there. I recently purchased my VK berlina with a 308 (black) motor. The engine was recenty rebuilt by the previous owner but he did not tell me if he rebuilt it with hardened valves and seats. Have been running the car on 95ron bowzer juice with fuel additive or would 98ron with no fuel additive be better. Cheers.:unsure: :bang:

P.S will update pics of my Commy soon.:w00t:

 

[vkberlina]

I have a question for all U VK nuts out there. I recently purchased my VK berlina with a 308 (black) motor. The engine was recenty rebuilt by the previous owner but he did not tell me if he rebuilt it with hardened valves and seats. Have been running the car on 95ron bowzer juice with fuel additive or would 98ron with no fuel additive be better. Cheers.:unsure: :bang:

P.S will update pics of my Commy soon.:w00t:

Personally if it was my car I would run it on 98-100 octane without an additive.
I have actually just stripped down, ported & freshened a carbie 202 head that has been run on 98 octane fuel since it was built approx 60,000km ago (needed stem seals basically), I checked the exhaust valves for signs of pitting and they were in excellent condition, a leakdown test showed very minor seepage which was recified by repasting in the valves.

I have said this on numerous occasions, what actually causes valve seat recession is combustion temps reaching a point where they actually cause the exhaust valves to glow red hot and soften, when the valve closes against the seat it cools enough to microweld tiny hotspots with the seat when the valve opened they tear appart causing very fine pitting over time causing valve seat recession.
The higer the octane fuel the lower the combustion temp meaning the valves wont get to a temperature that will allow this circumstance to occur. Considering your car was designed to run on 96 octane fuel, 98 octane will be sufficient.
Mind you is a car is poorly maintained experiencing lean outs or is miss timed etc using the correct fuel still wont help.

I will see if I can dig up some photos of valves to show what im talking about.

cheers
Scott