Please help, can I use regular gas in my new Hemi? Thank you
Octane for My Hemi
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Originally Posted By: bobbob
Please help, can I use regular gas in my new Hemi? Thank you
What does the owner's manual say?
Please help, can I use regular gas in my new Hemi? Thank you
What does the owner's manual say?
You can use whatever you want, might not be the right thing to do but hey its your car. why not follow the manual. my 300 as per manual, 89 is preferred but may use 87, i have used 87, 89, 91, 92, and guess what the car seems to run the best on 89.
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Originally Posted By: bobbob
Please help, can I use regular gas in my new Hemi? Thank you
I can tell you that the cheapest fuel will run well in it as it has very sensitive knock sensors. I am pretty sure 89 is recommended for all the 5.7's.
Please help, can I use regular gas in my new Hemi? Thank you
I can tell you that the cheapest fuel will run well in it as it has very sensitive knock sensors. I am pretty sure 89 is recommended for all the 5.7's.
funny you should ask. book says89 is preferred but 87 acceptable. i used 87 when i first got my truck. then one later i started using 89 for six months. same weather, same style of driving. no difference at all. i now use only 87. keep in mind in my world, we can only get gas with 10% ethanol.
Originally Posted By: SteveSRT8
Originally Posted By: bobbob
Please help, can I use regular gas in my new Hemi? Thank you
I can tell you that the cheapest fuel will run well in it as it has very sensitive knock sensors. I am pretty sure 89 is recommended for all the 5.7's.
Steve's right.
I had an 04. I could break 21-22 on the highway,in 4wd. City mileage was horrible.
I got worse mileage using regular and less pep. Great truck though
Originally Posted By: bobbob
Please help, can I use regular gas in my new Hemi? Thank you
I can tell you that the cheapest fuel will run well in it as it has very sensitive knock sensors. I am pretty sure 89 is recommended for all the 5.7's.
Steve's right.
I had an 04. I could break 21-22 on the highway,in 4wd. City mileage was horrible.
I got worse mileage using regular and less pep. Great truck though
Originally Posted By: bobbob
Please help, can I use regular gas in my new Hemi? Thank you
Which Hemi? Regular is OK for a 5.7, though it will perform better on mid-grade. The 392 is spec'd for 91, although I've inadvertently run about 60% regular / 40% premium through it and it didn't flinch.
Please help, can I use regular gas in my new Hemi? Thank you
Which Hemi? Regular is OK for a 5.7, though it will perform better on mid-grade. The 392 is spec'd for 91, although I've inadvertently run about 60% regular / 40% premium through it and it didn't flinch.
In my 2012 RAM 5.7 HEMI, 87 juice makes the most MPG. I've tried 89 and 93, "ZERO" driving difference and got less MPG.
I called RAM and asked why it says that in owners manual. Their answer was 89 octane was thought to have more detergents, thus better performing engine in long run. Think about it, "2" points octane is supposed to make a difference???
I called RAM and asked why it says that in owners manual. Their answer was 89 octane was thought to have more detergents, thus better performing engine in long run. Think about it, "2" points octane is supposed to make a difference???
As others have said what HEMI and what vehicle? Most of the 5.7L's say 89 is preferred but 87 is acceptable.
I had an 04 Ram and an 08 Ram both with the 5.7L. Manual said what I listed above. I tried both 87 and 89, in both trucks and multiple fills to get an accurate measure, and it made ZERO difference in performance or MPG. I ran the 87 in my trucks and it was just fine.
Check your manual and as long as it says 87 is ok run a few tanks and see how it does. If it drives fine go with it. As fast as a HEMI drinks gas 15-20 cents a gallon saved running 87 vs 89 adds up over time.
I had an 04 Ram and an 08 Ram both with the 5.7L. Manual said what I listed above. I tried both 87 and 89, in both trucks and multiple fills to get an accurate measure, and it made ZERO difference in performance or MPG. I ran the 87 in my trucks and it was just fine.
Check your manual and as long as it says 87 is ok run a few tanks and see how it does. If it drives fine go with it. As fast as a HEMI drinks gas 15-20 cents a gallon saved running 87 vs 89 adds up over time.
I would use what the manual recommends and any small differences in octane is easily adjusted for by the ECU mapping, it is set up to account for 87, 89, 91, and 93/94.
I had a coworker that got a Hemi Dodge Magnum the first year it came out. He used 87, 89, and 93, and he found that the 93 made the engine sound like it had a huge cam at idle, but it did nothing for performance or MPG. He went with 87 octane and was fine.
For those guys who ran a single tank of higher octane and claimed no difference it's because the ecu doesn't add timing instantly. It takes many run cycles for it to advance the timing to get back to full power.
My 2094 routinely got 21-22 mpg and that's without any cylinders shutting off or variable valve timing.
My buddy has an 08 and can't get better than 15mpg using regular. When I used regular I couldn't get better than 15mpg either.
It takes more than one tank to net an improvement. And I could feel the difference immediately with regular.
Believe what you want. High octane increases power and in my case miles per gallon.
My 2094 routinely got 21-22 mpg and that's without any cylinders shutting off or variable valve timing.
My buddy has an 08 and can't get better than 15mpg using regular. When I used regular I couldn't get better than 15mpg either.
It takes more than one tank to net an improvement. And I could feel the difference immediately with regular.
Believe what you want. High octane increases power and in my case miles per gallon.
We still drive cars in 2094? Geez, you'd think we would be past them by then........
Originally Posted By: Clevy
For those guys who ran a single tank of higher octane and claimed no difference it's because the ecu doesn't add timing instantly. It takes many run cycles for it to advance the timing to get back to full power.
My 2094 routinely got 21-22 mpg and that's without any cylinders shutting off or variable valve timing.
My buddy has an 08 and can't get better than 15mpg using regular. When I used regular I couldn't get better than 15mpg either.
It takes more than one tank to net an improvement. And I could feel the difference immediately with regular.
Believe what you want. High octane increases power and in my case miles per gallon.
Well, as I said, I ran multiple tanks of the 89 to see if it would make a difference and it did not.
For those guys who ran a single tank of higher octane and claimed no difference it's because the ecu doesn't add timing instantly. It takes many run cycles for it to advance the timing to get back to full power.
My 2094 routinely got 21-22 mpg and that's without any cylinders shutting off or variable valve timing.
My buddy has an 08 and can't get better than 15mpg using regular. When I used regular I couldn't get better than 15mpg either.
It takes more than one tank to net an improvement. And I could feel the difference immediately with regular.
Believe what you want. High octane increases power and in my case miles per gallon.
Well, as I said, I ran multiple tanks of the 89 to see if it would make a difference and it did not.
Originally Posted By: Clevy
For those guys who ran a single tank of higher octane and claimed no difference it's because the ecu doesn't add timing instantly. It takes many run cycles for it to advance the timing to get back to full power.
High octane increases power and in my case miles per gallon.
This is true, the ECU may take a couple of tank fulls to put the full effect of mapping for the different grades of gasoline.
However the extra power you get from 89 vs 87 and the MPG improvement is probably not noticeable just by feel and the improvement is probably tiny at best. Going from 87 to 94 might make a difference that consumers would notice at least at the gas pump if not in engine performance. Save your money and use the pump octane that the manufacturer recommends FIRST.
For those guys who ran a single tank of higher octane and claimed no difference it's because the ecu doesn't add timing instantly. It takes many run cycles for it to advance the timing to get back to full power.
High octane increases power and in my case miles per gallon.
This is true, the ECU may take a couple of tank fulls to put the full effect of mapping for the different grades of gasoline.
However the extra power you get from 89 vs 87 and the MPG improvement is probably not noticeable just by feel and the improvement is probably tiny at best. Going from 87 to 94 might make a difference that consumers would notice at least at the gas pump if not in engine performance. Save your money and use the pump octane that the manufacturer recommends FIRST.
The timing adjustment your engine makes automatically won't be much in terms of power adding. It simply plays with the timing until there is no knock - in lay man's terms.
Usually - you'd want to use the lowest octane fuel you can run without knocking issues. The ONLY reason you should go to a higher octane fuel is when you experience knocking issues (you'll notice power drop off and such... I'll skip the symptoms explanations).
I always get a good laugh at people who think running 91-93 in their engine designed for 87-89 will give them more power. All it does is slows the flame front which will decrease your torque (and thus power). It will also increase emissions and decrease fuel economy due to the fuel not burning as well and completely as it used to.
IIRC - The Hemi's in the Ram pickups have about a 10:1 compression ratio. This is somewhat high - but I'm sure the engineers would tune it to run on regular since it's a fullsize "work truck". I can not confirm this without further info however.
Summary - Run the lowest octane you can. Higher than required octane will simply degrade your combustion efficiency. Too low of octane will cause knocking, so you don't want that. If your vehicle was programmed to be able to run regular or midgrade (usually b/c it doesn't have forced induction or a high compression ratio - like most full size truck motors) than run that. Premium won't give you any benefits except a lighter wallet.
Usually - you'd want to use the lowest octane fuel you can run without knocking issues. The ONLY reason you should go to a higher octane fuel is when you experience knocking issues (you'll notice power drop off and such... I'll skip the symptoms explanations).
I always get a good laugh at people who think running 91-93 in their engine designed for 87-89 will give them more power. All it does is slows the flame front which will decrease your torque (and thus power). It will also increase emissions and decrease fuel economy due to the fuel not burning as well and completely as it used to.
IIRC - The Hemi's in the Ram pickups have about a 10:1 compression ratio. This is somewhat high - but I'm sure the engineers would tune it to run on regular since it's a fullsize "work truck". I can not confirm this without further info however.
Summary - Run the lowest octane you can. Higher than required octane will simply degrade your combustion efficiency. Too low of octane will cause knocking, so you don't want that. If your vehicle was programmed to be able to run regular or midgrade (usually b/c it doesn't have forced induction or a high compression ratio - like most full size truck motors) than run that. Premium won't give you any benefits except a lighter wallet.
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