Don Terrill’s Speed-Talk

I tried using regular vs high test in my 2008 corvette on different long trips to the same place. I lost between 3 to 4 MPG on regular because the computer changed the timing and you needed more throttle input to keep the same speed so I would guess they are correct.

If it does happen how much more compression will tolerated from 91-93. 10-1 to 11.5-1?

I believe it, my wife's car's static C/R is 12:1. Some knobhead out there is probably running it on regular telling all his friends its just a stunt by the dealer and never knowing he's missing power.

Higher C/R allows more thermodynamic efficiency and more work extraction from the burning fuel, and higher C/R needs higher octane. The progression seems logical..

Just be clear at what Octane.. RON? MON? R/M/2? What standard?

the NA corvette engine is now 11.5:1 super charged 10:1

Morgo wrote:Just be clear at what Octane.. RON? MON? R/M/2? What standard?

This year the VP of General Motors Propulsion Systems said, “100 RON fuel (about 95 octane in the US) is the right fuel for the 2020-25 timeframe.”

If they do it with real fuel it will be good but the way our stupid world works it will probably end up being an e15 on some conglomerate of crap that reduces fuel mileage and makes old cars obsolete.

there is no need for this 54 MPG crap as the world is awash in oil and this was Obama's way of curbing global warming.. just making it more expensive for the working man to buy a car. back in the 60s and 70s I bought a new car every year but I can not afford to do that now with the price of cars.

pamotorman wrote:there is no need for this 54 MPG crap as the world is awash in oil and this was Obama's way of curbing global warming.. just making it more expensive for the working man to buy a car. back in the 60s and 70s I bought a new car every year but I can not afford to do that now with the price of cars.

Yeah and it may be time to stop calling it fossil fuels, You can find several studies like this.
"Depleted oil pools seem to be renewing themselves inexplicably. Is petroleum a renewable resource?"
http://rense.com/politics6/replent.htm

Adding OEM water/methanol injection systems to OEM higher compression ratio and or supercharged cars would allow this without changing the refinement of the current gasoline.

The water/meth injection could be both direct in cylinder (mixed in with the gasoline by a pre-mixer system (naturally aspirated/high compression) and also injected at points in the induction system for intercooling effect at heavy throttle loads under boost.

One of the problems with water/methanol injection on naturally aspirated high compression ratio engines for knock resistance under load is the conditions, thus the actual amount of needed water is always changing. Computer EFI control and direct in cylinder injection
solves this. and by keeping the gasoline and water/Meth separate until right at injection it solved the fuel refinement cost difference. 50-50 water meth is safe in that form and tents to not degrade (attract water) like pure methanol or pure ethanol does. It it safe and stable much like winter windshield washer fluid. * about 30-35% methanol to water. This infurstructure already exists including at point of sale. * the gas station).
You'd refill the (under hood) tank just like you now refill your washer fluid now.
If you run low the car EFI computer tells the driver to re-fill...
The EFI system can just retard the timing till the system is refilled.

BMW already has a turboed car that uses a OEM Water/methanol injection system to allow both higher compression and boost on existing fuel.

One issue is that (processed) water is actually more expensive than gasoline is. (retail price)

Another path to higher engine fuel and power efficiency is a variable compression ratio engine.
I believe Volvo leads the way on that.

Although water/meth is a usable option, the 2 draw backs I see is it would increase the price of the vehicle beyond the already blotted pricing and the other is having the ability at every filling station for the average driver.

Proper fuel at the pump would be the best most cost efficient option.