: Time To Know 87-89-93 Octane

04-06-08, 01:57 PM
Starting to see questions about fuel grades. I have a 2004 ESV, book says premium grade (93) but it says it's ok with 87 octane, but they make it look like all hell will brake loose if you get bad quality 87 or lower gas knocking etc,let's see if we can set the record straight.

04-06-08, 03:46 PM
I can tell you this from experience, you will notice less power (it feels like you lose 100HP - I am sure it isn't this much, but very noticable) from your lade with less than premium fuel, but as long as you are going easy (no wide open throttle with a load) I can't imagine anything bad happening. I ran my truck for two tanks like this when my work beater (2000 Buick Regal) was getting some work done on it. My work commute is about 85 miles a day of easy highway driving.

Sorry ahead of time for the tangent that is about to come.

But let's think about the reason of why we are contemplating putting in lower octane; to save money because of the fleecing gas companies are doing to us right now. Let's say you put 20 gallons of fuel in your truck, the 20-30 cent per gallon difference is $4-$6 for that 20 gallons. Is it worth it to save $4-$6 when the bigg expense is the $75 it cost to even put in even regular fuel? At the end of the day the $3.70 per gallon is what is killing you, not the nominal difference in grades.

I use my truck to tow and can't lose power or take the chance. I have seen what detonation can do to a motor & pistons and it isn't pretty.

Sorry if I read too much into your question, but these gas prices are pissing me off. You realize they can charge us $10 a gallon and there isn't a damn thing we can do about it. US big oil made $110 billion in profits last year and our stupid government won't do a damn thing about it. GAS prices are the reason americans are in such bad shape and we are in a recession. I know I am spending $400-$500 a month in gas compared to the $100 I used to spend. That is real money that retail will never see and why a lot of americans are losing their houses. It just isn't poor loan choices.


04-06-08, 09:03 PM
If you use lower octane fuel the engine knock sensor will retard the timing to prevent knocking. With the timing retarded a couple degrees you may notice a little less pep out of the hole. No serious loss of power occurs.

eta: I always ran mid-grade in my Escalade regardless of the cost of fuel.

04-07-08, 09:09 AM
I have always used 87 octane in my 2005 and have not noticed an engine knock and the power seems to be on track with my Dad's 02 in which he uses 91 octane.

04-07-08, 06:51 PM
I'm stuck in the same situation 87, 89 or 93. The book says use 91.

I usually use 93. It always take $100 for me to fill my tank. I used 87 a couple fill ups and i definitely noticed a lot more lag.

When I'm on the way up to Vermont or any other long drives I fill up with 89 (87 sometimes) since I be on the highway the entire time and will use it up in a day.

Anyone know if mixing 89 and 93 will cause harm. (i.e. Fill up with 93. use half the tank, Fill up with 89. use half a tank fill up with 93, etc.)

04-07-08, 09:16 PM
think about this, usually using a lower grade octane you get fewer miles per gallon, so you have to do the math, run 1-2 tanks of each grade and keep track of your mileage and gallons used. you need to make about the same trips with each tank of fuel and the same driving style. figure up your miles per gallon, cost of fuel, then do the math and find out which fuel grade is the best for you. you might save a few dollars when you pump the gas, but you might be actually costing yourself money because of the loss of mpg. i use premium in my vehicle because i have a chip, it hurts when pumping gas but i can get 20-40 miles more out of a tank of premium versus a tank of midgrade.

04-08-08, 08:43 AM
As said above the truck calls for 91 octane, of course were I live it's 87, 89 or 93 octane, when I had my 03' I could really feel the difference in the mountains running 87 or 89 when compared to 93 octane, on flat ground you may not notice much difference, or course you have a high performance engine, would you be running 87 octane in your 2000-2004 Corvette if you had one, probably not and they had the same hp as the 2002-2006 Escalade's. :)

04-10-08, 12:08 PM
Over 50K on a 2003 ESV all on 87. Used high octane once and could not tell a difference.

04-10-08, 03:35 PM
i always use 89 and my 'lade has 110000 miles on it and no engine problems (knock on wood)

04-11-08, 10:16 PM
I generally use 93 in my 04 which has 100k on it.. Occasionally I'll run mid grade 89 but never 87..

I can't tell you I see much of a difference between the 89 & 93 but the premium is definitely better in the long run.. especially if you plan on keeping your truck for a long time.. Those gas company commercials you see about carbon build up, etc for do have truth to them..

It is true also that premium burns slower and will get you a little better MPG

The bottom line is this: Trust the manufacturer that engineered and built your vehicle. If they say to use premium fuel -- use it! You are running a high compression V8 engine.. especially us AWD guys with the 6.0.

If your owner's manual called for synthetic oil, would you question it and run regular oil instead, or a "synthetic blend"? No, I bet you'd run the synthetic.. So listen to GM and run the higher octane fuel..

If you were driving any CTS/SRX/STS/XLR you would have to run synthetic oil.. for some stupid reason the escalade is now the only new vehicle that Cadillac offers that uses regular oil -- all the rest call for synthetic.. Yet I bet that more than half of the escalade owners here are running synthetic oil in their escalades -- it costs more but gives you more bang for your buck and is better for engine longevity.. The quality of the fuel you run in your truck is no different and is no place to be skimpy..

These are just my opinions.. I agree with ScoreBo -- spend the extra $10-$15 that it will cost to run the good stuff..

Rollin on 22's
07-08-08, 02:23 PM
I've used 87 on my 06 EXT for about 9 months mostly because there wasn't the little tag that said 'premium only' like the ones in my previous cadillacs. But then I started thinking about engine longevity and began filling with 89. I can tell the difference in mileage for sure. BUT considering prices (:annoyed:) do I need to upgrade more? My plan is to drive this vehicle for YEARS. I'm in Indiana and commute several times monthly about 160 miles round trip.

07-08-08, 05:32 PM
What are some of the prices per gallon you are paying?? Here in Cali, we dont even have a 93 option anymore. 87,89 annd 91 are the choices. I started putting in 89 just because I have no idea what was the recommended octane. No manual and no stickers (stripped and repainted) came with the vehicle.

What I have been told is this....if the manufacturer (owners manual, sticker or dealer) says its recommended than that is a key that you can use other types...and yes...I believe there are advantages of running better fuel but, I don't believe that it will harm your engine. Now...if it says required or along those lines...be sure to use nothing but that or higher. That is what I was taught, told and try to stick with. Oh and btw...Prices where I live are about 4.60-4.70 for midgrade. 10-20 cents higher and lower for the others.

07-08-08, 06:40 PM
2006 ESV, synthetic oil, premium gas, manual said so, but the sales guy told me regular is okay. First 2 tanks were 87 Octane, and 91 ever since. Only a slight difference during quick acceleration, but that's important to me.

07-12-08, 01:16 AM
I know I can tell the difference with the higher grade gas, truck feels like it has a lot more go to it.