I'm sure you realize it's all about overhead , assets , labor and benefits cost but we usually don't take all of this stuff into consideration . Before I retired my hourly rate was $85. But being retired there are some other activities that take priority then doing a lot of stuff I don't feel like doing . How much is your hourly rate. Enjoy life 1st as anything else is secondary.

 

I think the dealers for many makes in the SW USA recommend fuel injector cleaning because of the god-awful petrol we get here. You cannot get 93 octane anywhere I've been in CA, AZ, NV and UT and the climate is such the stuff is degrading quickly just because of the heat. Oh, and in places that are properly in the desert you just cannot stop the fine dust from getting into everything. It's insidious.

 

That's probably the most half truths and myths I've ever seen in one single post.

The quality of your gas is no worse than anywhere else.

Fuel octane has nothing to do with quantity or quality of additives.

Your car achieves full performance on 91 AKI octane. Anything higher is pure waste.

High octane gas does not deteriorate any slower or faster than low octane.

Airborne dust has no effect on clogging injectors or engines.

Your dealer sell injector cleaning and other non Jag recommended procedures because of the high profit margin.

 

I think that may be the first time I've agreed with you Mikey!

 

Soooo...... I have to say I do like these guys at Rusnak. They messed up some hose and Eden, my service rep, called and 'fessed up right away. Their bad. They will fix. BUT.... this particular hose (somehow linked to the supercharger) has to be shipped from coventry. Car now not available til Monday.

So I am now giving an extended road test to the brand spankin' new XE with the supercharged 6cyl that they loaned me, with their apologies. I'm not a small 4-door guy, but I'm liking it so far.

I'll keep everyone posted....

 

Mikey,
+1

 

Ironically there is some half-truth there.
Shell V-Nitro additive package is only available in their premium octane- at least in USA.
And early test have shown it to perform as promised.
PRODUCT: Shell V-Power Nitro+ Test

 

Locally winter fuel produces more power vs the weaker summer juice. VOC's boil off in the heat and the EPA weeps so we get lower VOC stuff in the summer. You can smell the difference. Winter 91 octane fuel smell like race fuel. Summer doesn't.

 

Either you're joking or they are.

 

Mikey,
+1
I don't see how a fuel could contribute to "more turbo boost" unless the fuel is REALLY dirty and somehow jams the waste gate closed.

 

Turbo's spool on heat, not flow. Higher BTU fuel nets more turbine speed and boost, look at diesels. Ethanol based fuels have less BTU per pound vs. conventional stuff. Part of the myth that corn is better than dino but it doesn't give as much energy so you burn more for the same power and lose economy on cars that aren't tuned specifically for low BTU fuels.

 

True, but octane rating has no connection to the energy content of a given fuel.

The more I read the linked article, the more I'm convinced that it's joke. I think I'll stop.

 

Funny you should write that. I found similar humor in your post that higher octane gas has no different additive package.

I dont understand why that point is being conveniently buried.

 

Ranchero,
After the waste gate opens heat, speed, flow, etc do NOTHING to give "more turbo boost". The waste gate MUST be changed before the boost can be increased. Only then could you see "more turbo boost" from a higher BTU fuel.

MAYBE the RATE of turbo boost increase will be greater with higher BTU fuels. There is no way "Our (unscientific, but none-the-less user-based, and hopefully useful) consumer tests..." can show that. In any event, the maximum turbo boost is controlled by the waste gate, not the fuel.

I don't understand what you mean when you say turbo's spool on heat, not flow. If there is no flow through a turbine it will not turn, no matter how hot it gets. But that is a different discussion where we get into Boyle, Bernoulli, and Charles.

 

[QUOTE=Mikey;1676628]True, but octane rating has no connection to the energy content of a given fuel.

A higher octane rating allows the engine to run a larger compression ratio, which puts more fuel and air into each cylinder each time it fires. You are not getting more energy from the fuel, you are putting in more fuel.

 

It's not buried at all. The common belief that all high octane gas has more/better additives than all low octane gas is patently false. You found some hokey article trying to infer that this was not true. Very poor choice of a credible reference.

Do some high octane fuels contain more/better additives than some low octane fuels? Probably, if you looked hard enough.

It's also probable that some high octane fuels contain more/better additives than other high octane fuels. That's what the top tier marketing scheme promotes.

It's significant to note that neither Jaguar nor their past and present owners, Ford and Tata, endorse the top tier scheme at all. Practical experience indicates that our engines are not picky about additives- unlike some other brands. Yes Audi, I'm looking at you.

Why would a high performance engine inherently need more/better additives than a low performance engine? If we are to take the Otto cycle in it's purest definition, the less efficient low compression engine should be more prone to contamination.

 

Correct, with the additional element of potentially increasing spark advance all without running into significant detonation.

The message is that the octane rating of a fuel is simply a measure of resistance to detonation- and nothing else.

 

You are doing it again!
Shell's best additive package is ONLY available on their premium octane gasoline.

So your gross general statement that higher octane fuels dont contain different additives is just plainly wrong and bad advice.

P.s. Shell is top 5 in this country.

 

If we step back to the basics.
To derive 1lb of boost from cold air would cost over 1lb of drag on the exhaust- thus intake. So a zero sum gain.

You can run hotter and derive more energy with more complete combustion.

You are not increasing boost over the design capabilities- just not depriving it.

 

Turbos operate on pressure.
Heat is pressure and pressure is heat.
Hot air (which I am not blowing) is more pressurized than cold air.