When I first purchased my truck (05 Hemi) used with 22K mi on it, I used 87 for a few weeks because I never read the manual and didn't realize it required 89. I did notice hesitation at low rpms while gradually accelerating on the HW. Since then I have run 93 (only because BJs offers 87 or 93 and their 93 is cheaper than 89 at other stations in my area of MD). It has run much smoother since then. It is worth the extra few $$$ a fill up for piece of mind...

 

If you don't get it by now then you deserve to have your engine blow lol i always laugh at people who argue with the opinions of people that have researched this. And really its not alot of money.
I bet most people will blow 10X that on booze and going out in a year than the difference in price of 87-91

 

Some engines are equipped with knock sensor(s), usually located right behind the intake manifold. These are usually high compression engines that have software in the PCM to read the knock sensors and adjust the engine to run optimally for the fuel it's getting.

One example is the 4.7 HO, which has stereo knock sensors, one on each side. You'll get lower performance with lower octane, but you will do no harm to the engine. The HO version of the 4.7 has a compression ratio of 9.7:1, as compared to the standard version which has a compression ratio of 9.0:1.

My Grand Cherokee has the 4.7 HO, I usually run 93 octane, non-ethanol in it, but sometimes on trips, where I'm on the road all day and I'm gonna burn up the tank of gas on the interstate, I'll throw 87 in it to save a few bucks.

These are the ONLY engines with a compression rate over about 9:1 that I would consider running 87 octane in. Unless I was running a tune specifically designed to tune the engine to run on 87 octane. But you need to read the specifications on the tune, often it is not recommended to tow or haul with such a tune and low octane fuel.

 

I can sure feel the difference between 89 or 93 on everyday driving, even worst when pulling my trailer. On 93, I feel like that old Dodge commercial out running folks with my trailer. With 87, it'd runs okay but I do hear more pinging and slow response when gassing it. Now I just buy 93 at Costco which is at the same price of 87 at every gas station around here.

 

Now keep in mind (hammer correct me if im wrong), but these big box stores that sell premium that cheap is probably because its got alot of additive. There is a difference in real gas and ethanol enhanced gas....there are a few places in my town that claim real gas....and i have tested them and yes i get about 20-30 miles more per tank filling up there vs. other places....aka Sams, Costco, etc.

 

Look at NJ prices of $2.75 per gallon of 89 octane EXXON, October 2010, I had no problem with $80/ week. Now, I got Exxon NJ price $4.09 per gallon for 89 octane. I WANT TO SWITCH BRANDS. The local Sam's club sells P.P.P. for $3.79 per gallon, BUT IT IS 93 octane. The manual says DO NOT RUN Higher octane in your new 2007 Ram Hemi poor economy and performance will result. What's your thoughts? 9.6 to 1 Comp Ratio and 93 is too much. This $130 per week is tough sledding. Thanks, Mike
P.P.P is Premium Panther Pi$$.

 

I don't know how it's possible to get poorer fuel economy and worse performance from higher octane fuel. Now if the engine is tuned for 89, it's entirely plausible that any higher octane will offer no benefit, but I just can't see how it will hurt you.

My '04 manual states pretty much that, that running an octane higher than 89 will give you no benefit.

Hell, I got a good buddy with a late '90s Z71, manual states 87 octane as the GM 5.7 (350) is a fairly low compression V8, he has had it since it was 1 year old and he swears by high octane and has NEVER put anything less than 91 octane in it (and mostly uses 93 octane). The thing had right around 190,000 miles on it when I was in it last in February...

 

I want fuel stamps!!! Lol. @210 miles per tank that hardly last me a week only driving to work and back. Economy sucks. And its supposed to be up to $5 a gallon by memorial day?! WTH!! Its $3.899 here and thats for 89. Theres going to be alot of trucks at dealerships soon. Should be able to get a good deal!

 

Yep, thank your local politician!

It never ceases to amaze me how many people go upside down and lose their a$$ trading their trucks when gas goes thru the roof! Most often, it'd be cheaper to buy a beater 4 cylinder or motorcycle than it would be to trade the truck.

Got a family friend who panicked, traded his '06 Ram in '08 when prices hit $4 a gallon, owed WAY MORE on his truck than was offered in trade. Traded it on a slightly used Honda CRV and had the $6k difference in what they allowed for his truck vs. what he owed tacked on to the price of the CRV. Because EVERYBODY was buying these little SUVs when gas got high, they also only discounted the CRV about $300 off full list!

When gas went back down under $3 a gallon, the reality hit him that he owed like $25k on a vehicle with a KBB avg. trade was around $16k and the vehicle was too small for his needs and he hated it.

Could have either bought a LOT of gas for that $6k beating he took on the trade or bought him a nice little beater 4 cylinder.

People do stupid things when they panic...