Is cheaper fuel a false economy?

[Scuba_Steve]

Regarding petrol additives, I only fill up at Caltex because their petrol includes the Techron additive. These additives keep the intake system clean, whether it's carburetted or injected. They reduce carbon build up on the back of the inlet valves which can absorb fuel on start-up (making starting harder) then release the fuel as they warm up (producing rough running). As well they keep the pintle of the fuel injector clean ensuring an even and correct spray of petrol from the injector - this can give better fuel economy or higher power output compared to an engine with restricted injectors.

But all companies have additives Shell used V-Power, Z's about to use ZX, BP has their Ultimate (98 & Diesel), Mobil has Synergy & like you mentioned Caltex has the Techron.

[Asher]

This just popped up on my fb from Z:
"the additives are added at each terminal. Generally the base fuel is the same and then we add our specific additive at the gantry, different levels for different fuel grades. We have our own additive tank at each terminal that we blend into the fuels."....."ZX Premium has the same clean up and keep clean performance properties V-Power had - the key difference is this new additive we selected has a specific friction modifier component that helps improve engine efficiency by reducing friction between the cylinder liner and piston rings."

[SMOKEU]

Regarding petrol additives, I only fill up at Caltex because their petrol includes the Techron additive. These additives keep the intake system clean, whether it's carburetted or injected. They reduce carbon build up on the back of the inlet valves which can absorb fuel on start-up (making starting harder) then release the fuel as they warm up (producing rough running). As well they keep the pintle of the fuel injector clean ensuring an even and correct spray of petrol from the injector - this can give better fuel economy or higher power output compared to an engine with restricted injectors.

This just popped up on my fb from Z:
"the additives are added at each terminal. Generally the base fuel is the same and then we add our specific additive at the gantry, different levels for different fuel grades. We have our own additive tank at each terminal that we blend into the fuels."....."ZX Premium has the same clean up and keep clean performance properties V-Power had - the key difference is this new additive we selected has a specific friction modifier component that helps improve engine efficiency by reducing friction between the cylinder liner and piston rings."

It's all marketing hype as far as I'm concerned.

[SimJen]

Mumbo jumbo marketing hype!

[ducatilover]

Avgas stuff

Was working on an old Mitsi last weekend running on avgas, seemed to go fine. Then again, it was tuned for it.

I think with many performance cars, the engines can alter the spark advance sufficiently to to extract more power from each unit of petrol. I don't think it's specifically due to compression ratio but obviously timing will be retarded if knock is detected with using a low octane petrol and pre-detonation occurs.

Only way it's going to be properly useful advancing the timing etc is with the use of a wideband O2 sensor really, otherwise it's just guess work as to what the A/F ratio is. Kind of annoying and expensive, I prefer my carbs and ignition advancer

[Old Steve]

Until Caltex tells me what Techron is, its just witches brew and is being added for marketing purposes. From time to time I do add a squirt of valve master to my petrol powered vehicles. It was originally marketed as a fuel system detergent. The dose rate to prevent VSR is a lot higher than needed to clean fuel deposits.

Techron is the marketing name for an Oronite Chemicals (a division of Chevron) gasoline detergent additive. It is in there and it works. That BMW test run on NZ petrol had the Techron additive added to it. They weigh the inlet valves of a 300 series car, run it for ten thousand or so miles on the additised gasoline, then strip the engine and inspect and reweigh the valves. As I said, unadditised petrol leaves carbon deposits on the back of the inlet valves which cause poor starting and rough running because they absorb and release fuel, and leaves deposits on the injector pintle which cause an uneven spray pattern which reduces power and increases fuel consumption.

The 4 valves on the Caltex test car had weight gains of 0.00 gm, 0.00 gm, 0.00 gm and -0.05 gm, so one valve was infintessimally cleaner than it started and the other 3 gained no weight at all. BMW had not seen anything like it. Some of that result was due to the quality of the Marsden Point petrol, it had a low olefin level. But that Techron additive does work. The detergent in Techron additive keeps the valves, injectors and carburettors clean, the engine runs more efficiently.

Back in the 80s I had a friend who had a Ford Telstar Sports, and it's performance would drop off in about 5000 km. He would add some Techron concentrate and the performance would be back as new. Eventually he started going out of his way and filling with Techron petrol at a Caltex station and he never had the problem again.

I don't use anything other than Techron petrol. Irrespective of price. Bottom line.

Valve Master is a valve seat lubricant. It has no detergent properties whatsoever, it was made available when ULP was introduced to ally fears that cast iron engines without hardened valve seats would suffer valve seat errosion because lead (a valve seat lubricant) was being removed from petrol. In a car with an aluminium engine the valve seats have to have hardened inserts to prevent valve seat orrosion or resession, there's no need to use Valve Master on an aluminium engine. Nor on cast iron engines which do not have hardened valve seats unless they are running for long periods at high revs and maximum power.

I don't know if Mobil use detergent additives, I think Mobil's Synergy is just a brand name - I could be wrong. BP and Z do have a detergent additive in their petrol. The additive is added at each terminal, in cases where one company picks up petrol from another company then their additive is not included because the supplying company does not have the product and metering equipment to add the specific additive. This is fairly common, particularly BP which I think picks up 95 from other companies a lot - their storage at some terminals being only 91 and 98.