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As a new Hemi owner I'm asking what grade gas does everyone put into their Hemi?

Here in the UK we have two grades 95 octane and 98 octane

I've been putting the 95 Octane in the tank...is this what should go in?

Cheers
 

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UK Commander said:
As a new Hemi owner I'm asking what grade gas does everyone put into their Hemi?

Here in the UK we have two grades 95 octane and 98 octane

I've been putting the 95 Octane in the tank...is this what should go in?

Cheers
I may be way off here, but I always put the lowest octane possible (that'd be 87 octane here). I was told that the hemi is really a truck engine and it would run too hot on higher octane fuel.

Anyone else with some insight feel free to correct me.

:)
 

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The hemi requires the mid grade here which is 89 octane. Have you looked in your manual to see what the required octane is for over there?
 

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CrzCajun said:
The hemi requires the mid grade here which is 89 octane. Have you looked in your manual to see what the required octane is for over there?
Well I'll be danged.... I really should read this thing *pointing at owner's manual* more often.....

:eek:
 

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Morgan said:
Well I'll be danged.... I really should read this thing *pointing at owner's manual* more often.....

:eek:
I would read it, but its 75miles away at home, I'm in the office killing time and thought I'd ask my forum chums a question!!!!! :p

Who's reads the owners manual anyway??? :D

Sorry for asking a question!!! :rolleyes:
 

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you should be fine. isn't european gas octane different then USA gas grades. or am i missing something?

did you trade your CRD for the Hemi?
 

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don't you guys still have leaded gas as well? i thought i saw leaded gas when i was there from 98-2000. we accidentally put it in out car. P-reg. vauxall corsa.
 

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Discussion Starter #8
4.7commander said:
you should be fine. isn't european gas octane different then USA gas grades. or am i missing something?

did you trade your CRD for the Hemi?

Chrysler UK did a swap with the CRD. It had cost them so much to replace the transmissions, they wanted it off the road!!!

We have unleaded here now and have done for many years now!!!
 

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I looked up the difference between US and European octane ratings, so we can compare apples to apples.

The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane rating, shown on the pump, is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, the octane shown in the United States is 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, is 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and some even deliver 98 (RON) or 100 (RON).
 

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Mmmmm....confused even more now! :confused:

Called the wife, she states the operators manual is US spec! :confused:

I'll have a look when I get home!!! :confused:
 

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According the Riddle's writeup, you are good at 95 which is equal to our 90 here. The hemi's here require 89.
 

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I would assume that if you have two octaine levels you will want to be running the higher level fuel for the HEMI. We have three levels and run the middle or upper depending on preference.
 

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I've been using 87 octane in my HEMI since I bought it (new) with no problems. Tried a couple of tanks of 89 but could not tell any difference.
 

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The 4.7 liter version was the first of this family, appearing in the 1999 Jeep Grand Cherokee. The displacement is 287 cubic inches (4698 cc) with a bore of 3.66 in (93 mm) and a stroke of 3.405 in (86.5 mm). It has a cast iron block and aluminum "almost Hemi" heads :D with two valves per cylinder. It uses a chain-driven overhead camshaft. It originally produced 235 hp (175 kW) and 295 ft·lbf (400 N·m) of torque.

The PowerTech was on the Ward's 10 Best Engines list for 1999.

Applications:

* 1999-present Jeep Grand Cherokee
* 2000-present Dodge Dakota
* 2000-present Dodge Durango
* 2002-present Dodge Ram
* 2006-present Jeep Commander
* 2007-present Chrysler Aspen
 

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"Almost" only counts in horseshoes, hand grenades and nuclear weapons!

The Allpar article said that the only difference is that the cylinder head has a flat wall on one side, but that everything else is the same as a Hemi. I just wish they'd redesigned the engine for the 2006-2007 years, that extra power would be nice. But there is a supercharger for our engines, hmmm...
 

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I also run the low grade in my HEMI and have had no issues. I did try the "good stuff" and I think I actually lost MPGs and performance (and $$$)!
 

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My HEMI is at 45k miles now... Been using Octane 87 for 75% of the miles. I'll put in Chevron 91 Octane once in a while (contains Techron for cleaning purposes)
 
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