Higher Octane Gas, Mileage & Gas Prices.

[Captain Virgil Hilts]

There were a few Cadillacs with the LT1. I have a friend who worked at a Cadillac dealership. A couple of guys in the cleanup department got fired for doing funny car style water burnouts in new cars. The Cadillac built on the same platform as your Buick will have an LT1. I think they were Fleetwod Broughams.

The ragged 4.1 engine did suck, the 4.5 was not too much better, the final version, the 4.9, was decent.

[JTs]

heres what i run i my ride.

Cat 3406E
Cylinders: In-line 6
Aspiration: Air-to-air
Bore x stroke: 5.5 X 6.75 in.(140 x 171 mm)
Displacement: 966 cu. in. (15.8L)
Dry Weight: 2867 lb (1301 kg)
Valves/cyl.: 4
Fuel System: Caterpillar EUI

it makes 600 hp stock from cat but i have o/c ed it to 800
runs great on cetane 43.  only gets 5.5 mpg. we put 1 quart of trans fulid in the tanks every 10k to keep injectors clean.  ripsnort we got ya beat on fuel tanks pair of 200 gallons.

[Ripsnort]

Originally posted by Westy
And kudos to the House of Reps for approving a massive energy plan which included billions in tax breaks and subsidies to energy companies (like Exxon/Mobile).  Lawd  knows they needed it! Must be part of that trickle down economy thing they've been talking about for the past 4-5 years.

How DARE they pass a bill that would stretch America's gasoline supplies and make us less dependant on foreign oil supplies!  Those bastards! The house wouldn't even vote approval to protect those big bad oil companies from liability lawsuits! WHy, do we really need a diverse mix of fuels? Do we really need to create jobs and spur development of cleaner burning coal and provide a new generation of nuclear reactors? Hell no!

Oh, and this just in....those oil companies are gonna make money because they are in the E-N-E-R-G-Y business!

And the farmers! Those bastards are gonna make money hand over fist producing corn for methanol!

Energy bill backs ethanol, not oil savings plan

Source: Copyright 2005, Reuters
Date: July 25, 2005
Byline:  Tom Doggett and Chris Baltimore





WASHINGTON (Reuters) - To stretch America's gasoline supplies, the leaders of a joint Senate-House conference committee racing to finish a U.S. energy bill agreed on Monday to almost double production of the motor fuel additive ethanol to 7.5 billion gallons a year by 2012.


Rep. Joe Barton, Texas Republican and chairman of the energy bill conference committee, proposed creating an $11.4 billion fund to clean up MTBE contamination in return for shielding refiners such as Exxon Mobil Corp. from lawsuits. But the plan was roundly criticized by the oil industry, municipal water officials and key U.S. senators.

While Barton did not win liability protection for the oil companies, he was able to include draft language in the bill to require MTBE liability lawsuits to be reviewed by federal courts, setting a higher bar for such lawsuits to proceed.

White House spokesman Scott McClellan reiterated on Monday that the administration "doesn't think we need to be providing tax credits to oil companies when the price of oil is above $50 a barrel."

Bush spoke with leaders of the conference committee on Sunday and urged them to approve a final energy package this week so the full Senate and House can clear it and then send it to him to sign into law by Aug. 1.

[culero]

This is one of those subjects where both sides can be right, to some extent.

Sava....Virgil Hilts knows what he's talking about. His advice regarding hardware-related factors is spot on.

However, it doesn't take modern engine management systems as implemented in most "fuel injected" (its not really fuel injection but that's another discussion) vehicles into account. There's a capability of these systems that some refer to as "adaptive strategy". Basically, the management system is designed to push timing and fuel delivery toward what's best for performance while remaining within emissions parameters and avoiding detonation. These systems can and do allow most modern vehicles to take advantage from higher octane fuel.

Note I said "most" and "modern".

On the Pontiac V8s, yes compressions in the 10*/1 range were only 1970 and prior. My box stock 1971 TransAm with the 455HO was 8.4/1 as built, and responded really well to the .030" I took off its cylinder heads

culero

[culero]

Originally posted by Captain Virgil Hilts
The ragged 4.1 engine did suck, the 4.5 was not too much better, the final version, the 4.9, was decent.

The only good thing about the 4.1 was its too-soft main bearing inserts. Owners hated the fact they started experiencing crankshaft knock at 60-80K miles, but shop owners (like me, in those days ) loved those gravy main insert replacement jobs (its a really easy job on that chassis and with generous flat rate times).

They wised up and fixed that by the time the 4.5 came out.

culero

[eskimo2]

Thanks,

My Volvo is a fuel injected 4 cylinder.

I just pulled out the owner's manual. It says:

(Paraphrased)
�Volvo engines require unleaded gas with an (R+M)/2 (AKI) rating of 87 or higher. This is generally equivalent to a RON of 91 or higher.

Volvo recommends (R+M)/2 of 91 for high altitudes and hot climates.�

So I�m gathering that it�s not worth bumping up the octane unless it�s really hot?

I�ve been getting only 20 mpg lately; although I�m often hauling a rowboat on the roof, that can�t help the mileage much.
I just had it tuned up a few days ago; I should see how it does now.

[culero]

eskimo, I'm not very familiar with Volvo, so I can't predict results. While the same physics govern all makes, its the sophistication of design in the management system that controls your "fuel injection" that determines whether or not your car that's rated to run acceptably on regular fuel will experience performance benefits from using premium fuel or not.

I can tell you that the vehicles the US "Big Three" built from the late 80s through the end of the 90s (at which point I made a career change and stopped remaining current on the technology) mostly were vehicles that to some extent (varied by model) would get better mileage on premium fuel than regular. Only their cheapest models used systems that wouldn't optimize performance to take advantage of the extra octane. My experience was that 1.5 to 2 MPG better at cruise speeds was typical.

But its a "YMMV" situation. I would recommend you experiment by tracking mileage carefully over a period of several tanks with both grades of fuel and compare results.

Another observation I always made based on the anecdotal evidence I saw was that engines I inspected that I knew were always run on premium fuel seemed to have much better internal cleanliness (especially in the combustion chamber but also to a lesser extent elsewhere) than vehicles that always run on regular fuel. Since I'm miserly and always stretch vehicles to their limits in terms of endurance, I see this as significant in my personal decision to use premium fuel.

You need to understand that all manufacturers have an imperative to design for, build for, and recommend usage of regular fuel as acceptable. Consumers would (with the exception of buyers of "high performance" vehicles) see the requirement of higher octane fuel, or even the admission that the vehicle won't run as well on regular as it will on premium, as a disincentive to sales.

Most people accept that engines last longer when oil change intervals are smaller than manufacturers recommend. I can certify that's true. Manufacturers recommend the least amount of maintenance that will yield barely acceptable results for the reason of minimizing expected costs of operation when selling vehicles. The fuel thingy we're discussing is relevant to that.

culero

[SFRT - Frenchy]

Culero, u still have the 1971 T/A? BTW, I'll be in Mc Allen every week day around 8am:D

[eskimo2]

Originally posted by culero

Most people accept that engines last longer when oil change intervals are smaller than manufacturers recommend. I can certify that's true. Manufacturers recommend the least amount of maintenance that will yield barely acceptable results for the reason of minimizing expected costs of operation when selling vehicles. The fuel thingy we're discussing is relevant to that.

culero

On that note, I read a Consumer�s Report article that compared oil change frequency and engine life.  They ran cars with oil changes at varying intervals (like 2,000, 3,000, 6,000 & 10,000 miles).  After 100,000 miles they tore the engines apart saw no difference in wear between the 2,000 mile oil change cars and the 10,000 mile oil change cars.  They suggested that the major proponents of 2k or 3k oil changes were the oil companies and oil change services.  Since reading that article I change my oil about every 10,000 miles or once a year.  

eskimo

[culero]

eskimo, I've seen BS in Consumer Reports so many times I quit looking at it. I have no interest in oil sales but I do have 25+ years experience doing vehicle repair. My experience tells me something different.

Frenchy no, I sold the TA in 1981, something I lived to regret (I miss it). I now drive a diesel-powered Ford Tempo.

I do know the good breakfast spots here, tho

culero (my e-mail addy here works)

[eskimo2]

So how often do you think oil should be changes?

eskimo

[J_A_B]

"So how often do you think oil should be changes? "

IMO it depends on how hard you run the engine.    

J_A_b

[eagl]

I still try to change the oil every 3000-4000 miles for a few reasons.

First, it's cheap insurance.  A new LS1 motor would run me at least $6000 and an oil change is $15.

Second, every time you hear a story about some guys car lasting an amazing amount of time, you'll find that he's done the 3000 mile oil change thing.

Third, having fresh oil in there isn't necessarily going to reduce overall engine wear, but chances are that at least one part of your engine is on the edge of manufacturer's specs, and it's that one part that the oil changes can keep from going bad.

Fourth, engines don't just "wear out" very often.  Some part wears enough for it to break, and the amount of wear it takes to break something varies from part to part and from engine to engine.

I could go on and on, but I'll end with the observation that my Dad used to be lax with oil changes and therefore nobody was suprised when he engine threw a rod, and my firebird has 103,000 miles on it and doesn't burn ANY oil between oil changes, even on the odd occasion when I don't have time to get the oil changed and it goes up to 6000 miles between changes.

I almost forgot...  Oil looks, smells, and feels different after about 3000-4000 miles.  If there is a difference that I can detect in the composition and contaminant content, then I assume there is a difference in how good it is for the engine.

I'm not a purist about it and if someone wants to push the limits and delay their oil changes, then that's just fine.  I'll take the cheap insurance and point-and-laugh when I hear about people who's engines die.

[Captain Virgil Hilts]

Originally posted by eskimo2
On that note, I read a Consumer�s Report article that compared oil change frequency and engine life.  
eskimo

Consumer Reports once rated the Corvette as extremely poor for BODY RUST. That's just one of a hundred BS ratings and rankings I've seen in Consumer Reports.

IF you want to go to 5K miles between changes, use something like Mobil 1 or Royal Purple synthetic. And a premium (not Fram or store brand) oil filter.

Mineral oil is crap after about 3500 miles. The additives are gone and the oil itself has heat breakdown.

[B17Skull12]

i really don't think you need. Only thing we buy high octane for is for our 2 stroke dirt bikes.  I thing the only reason we buy that for them is because their engines need those high rpm's to actually move (10,000-12,00 ish).