I figure I would post this here after there are no search results on the topic of using other fuels for the modded V6 & V8 motors.

Has anyone tried alternate fuels stock and then modded to see if either helps enough to justify the cost of the gas?

I have a few cans left of this race gas that I used for many other reasons an was curious if the stock or tuned ECU would take advantage of it in the Jags?
RACE GAS | Racing Fuel Concentrate

I used his to get close to 105 unleaded in other cars and it really helped give a slight edge on stock and tuned 997 TT Porsche so I figured maybe it would help the jag possibly?

Or maybe even use a real unleaded race gas instead of this additive like VP101, C85 or even their extreme 111?

Please chime in or link another thread if I overlooked a fueling thread somewhere on here.

I am interested to know some facts if using a unleaded race gas addictive or straight race gas indeed nets power gains in this drivetrain?

 

First, the various canned products sold in auto parts store is a complete waist of money. It's a marketing gimmick. The tiny little can isn't going to make a difference.
Second, it's my understanding that these engines were tuned using 91 grade octane fuel, so adding/using a higher octane is again a waist of money, unless the ECU is specifically tuned for the higher octane number fuel.
Guys, am I right or wrong.
Others will chime in, I'm sure.

 

It really depends on how hard you drive your car. Day to day 91 is fine. Unfortunately due to the smog ***** here in california, 91 is the highest we get. On the few track days I have participated, I usually use 93 (sold at the track) to prevent the engine from pulling timing and reducing performance.

 

Can't comment on what is the maximum octane our cars can automatically tune to; I use 94 but mostly cause I hate ethanol. ...but ditto on Ubad2's comment on the canned additives; they make VERY little difference......like maybe 0.1 octane used as directed.

Dave

 

I've seen no evidence that using fuel higher than 91AKI with a stock tune makes any difference. Nor should it.

 

As mentioned, a little can of additive won't do squat. You'd need a gallon of the 111 to raise your octane by 2 points on 10 gallons of gas. The days of canned octane went away with tetra-ethyl lead.
Unless you are somehow increasing compression, racing gas won't do much for these cars.

 

Wait, our cars are tuned for 91? I've used nothing but 93 the past 10+ years as all my cars prior have required Premium. Would there be a downside to using 91 instead?

 

In some states (California) 91 octane is considered premium gas.

 

I just wish we could buy it without the ethanol cr*p in it...

 

Are there no Fastback gas stations in your state or is nonethanol not legal? How about at boating locations?

 

There's a brand new Racetrack station that opened a couple weeks ago that I went to the first time yesterday. There were 5 pumps! Regular, Plus, Premium; Diesel; and a "no ethanol." I didn't pay any attention to the no ethanol option but next time I'll try it out!

 

luckily (and for now!) I have two non-ethanol choices: 91 Shell V-Power and 94 Chevron Premium. I don't use ethanol contaminated fuel in my boat, motorcycles, chain saw, leaf blower, weed wacker, generator, MB SLK or my Jaguar...and our two DD's are both diesel. :-)
Dave

 

Soooo.... why does everyone hate ethanol here?

 

...it's not just here. I hate it because I've had problems with my small engines and ethanol screwing up the carburetors.....can't see an upside to it from an engine/fuel system perspective.

Dave

 

That's completely understandable. Small engines/carburetors are rarely built to handle the corrosiveness of ethanol and often sit for long periods of time which can lead to gumming/clogging of rubber and plastic parts such as fuel lines.

For automotive applications (performance speaking) ethanol has massive benefits. If you tune your car for E85, its almost like running race gas all the time. Ethanol has an 105 octane rating compared to regular premium pump gas which ranges from 91-94. Modern vehicles are built to withstand ethanol based fuels and don't suffer from the same issues older vehicles/small motors do.

 

I'm aware of all that. 2 things;

- 1) I don't believe my car is tuned or able to use any benefits of increased octane

- 2) my car sits for several weeks at a time plus 6 months over the winter and while I realize the car isn't as subject to the negative effects that ethanol has on my smaller/simpler engines, I don't see any benefit to it either and non-ethanol fuel is more stable and has less moisture issues.


....so as long as I can buy it, I will.

Cheers,
Dave

 

Exactly.

Those in the opposition always go for the argument that "modern vehicles",
blah-blah can, in so many words ... tolerate ethanol. They can state
no benefit.

If there is no upside and a potential downside, a rational person seeks and
chooses an alternative with no downside. That would be the ethanol free.

As a turkey day example, sure you can tolerate your mother in law,
who with one slip of the tongue on your part can turn on a dime. That's
the downside. But maybe you'd rather spend the day with your best buddy
working on the car with a couple of beers. No downside there.

 

That is a corner case application requiring multiple changes
including custom tune, fuel injector replacement, and fuel
pump augmentation. It would be applicable to a handful
of owners.

Have you done it?

As for the latter part, E85 voids your warranty.

At least Nissan has had NHTSA mandated recalls involving
the use of ethanol at normal pump grade levels. Pinholes
in the fuel rail squirting gas over the engine is somehow
considered unsafe. They were 2007 model year. Certainly
within the range of what is touted as "modern, designed
to be ethanol tolerant" vehicles.

 

I apologize for creating a fuss; since this thread was started specifically around the topic of higher octane rating, I was surprised to hear so many people saying they "hate" ethanol. However, no one really specified why, which is the reason I asked. I totally understand its uselessness in unmodified engines; its just included to increase profit margins on the gasoline sold at the pump for oil companies. But as far as performance is concerned, ethanol has a huge benefit in a higher octane rating, and thus extremely useful to performance enthusiasts. You see why I questioned now.

Indeed I have done it before; I used to own a BMW 135i running on E85. Pretty standard in certain car communities, with some tuners (ie. Cobb Tuning) offering it as an off-the-shelf option to convert ones car. The f-type community is much smaller, and I imagine we just haven't had anyone willing to test the limits of the system yet. E-85 requires higher injector duty cycles, and if there isn't any space for that it's useless. But when done properly running a specific e-85 tune can increase power/torque as much as 10% with no other changes, thanks to the ability to safely run a much more aggressive ignition timing.

 

I understand your reasoning and know that you have well supported points.

I also know that you're wasting your time trying to convince people that ethanol (E10) is not actually Satan Incarnate. They'll always point to boats or garden tools (which can suffer problems with E10 if misused) and make an assumption that same will happen with their cars.

Good luck.