Re: What kind of gas?

Are you saying it takes intelligence to get a hazmat endorsement on a CDL class A? There is a pool of about 90 questions, out of which (depending on state) 15 to 30 will appear on the written test (some states computer generate the test, most just print out the same questions). ALL of the questions are rote memorization, and most of them are redundant with half the other questions. Tanker endorsement is not significantly different from the combination vehicle test, or doubles endorsement test. They are only slightly harder to ace than the basic test.

To tell you the truth, I have a 94 Cherokee 4.0 I6 and I find that with 87 it runs just fine, but it seems to run slightly better on 89. A little better on the power and gas mileage. As far as companies go, I'd say to shop around. Usually the expensive gas isn't always the best. But try a few places, and see for yourself how your Wrangler responds. You might be suprised.

GL with the TJ

We have been through this before in this newsgroup. I believe that the verdict was that some year models had knock sensors, which would indeed allow them to run better on premium than on regular, assuming that the programming and timing adjustment allows for this. The newer models on the other hand do not have knock sensors, and will run great on anything that does not make them "ping." That includes TJ's.

Earle

I say that pulling up to 80,000lbs of anything through crowded residential areas, over freeways, over mountain roads, & roads like those of the Feather River Canyon (all in one day - & sharing these roads with really unintelligent drivers) does require skills that many average or even above average individuals do not posses.

Advancing the timing might make your engine run better. If you put higher octane fuel in, and the knock sensor was keeping the timing retarded, then you might realize some benefit.

Earle

transmission

Approximately 9/7/03 19:43, Masterbiscuit uttered for posterity:

Dunno who else notices this, but have a similar issue, the I-6 pings mildly with California versions of 87 and stepping up to 89 seems to cure this. Once east of Nevada, it seems to run well on 87 even at high Utah/Colorado altitudes. No idea why.

My non-jeep cars (two subarus) run like s*it on anything but 87...

"skill" does not imply "intelligence"

You have more air down there, and the effect is similar to being at the same altitude but with a greater compression ratio. "Regular" is 85 or 86 octane up here, and most of the newer fuel injected cars seem to run fine on it.

Earle

Approximately 9/8/03 11:40, Earle Horton uttered for posterity:

Yeah, but what is wierd is that the Oregon and even Arizona gas don't ping down around the bay area. It isn't a heavy ping enough to bother, just the tick tick tick that you used to get with a stickshift when in the wrong gear and running aggressive advance.

I see two different things here in Colorado. They require oxygenated fuel (ethanol, now) in winter and there is a small but repeatable mileage gain - maybe .5 to 1 mpg - going from the base 86 octane they sell here to the next higher level. I also get better starting on cold days with the higher grade. Nothing earthshattering, but noticable. During the summer months when the fuel is NOT oxygenated I can see no perceptible difference period.

When I head South from here to Texas I get a noticable boost in mileage and apparent power (passing acceleration) that doesn't exactly track the altitude lose. I see a difference when I fill up east of Raton where the gas is not oxygenated and is 87 octane base, but as above that difference is far less noticable when the change is just 86 octane to 87.

From what I see with the two scenarios, I have to conclude that the ethanol is far and away the major performance degradation and that the octane makes virtually no difference. The 88 Jeep manuals make a point about needing higher octane when towing or other heavy load situations. I could see that yesterday running steep (8% or so) grades above 10,000 feet. WOT in higher gears actually seemed to lose pull while running the same RPM in a lower gear left me with plenty of reserve. Next time I make that run I'll try high test and see if it makes any difference since I do have a working knock sensor.

First, I agree that you should read your OM and use what it recommends. But I'm pretty sure in 1978 most gas stations did not offer 87 octane. Back then there was just regular unleaded (89), super unleaded(92/93), regular leaded (89).

True. Skill and intelligence certainly compliment each other...

Skill: "You're very bright."

Intelligence: "Thanks, you do nice work."

"intelligence".

ok..........are we equating skill with "eye - motor coordination" It would, then, seem that skill is required to shift, steer, etc & intelligence is required to prevent the multitude of potential traffic fatalities (driver sitting @ intersection & pulling out in front of you because he doesn't want to be behind a "slow" truck).

I'm too scared to drive slower than the artics !

In addition I am sure they know how to pour the right color of gas down the right hole at the station. That doesn't mean they know how it is blended or what else goes on back at the refinery.