93 vs 89 Octane
#1
Super Member
Thread Starter
Join Date: Jul 2017
Location: Houston Texas
Posts: 530
Received 153 Likes
on
136 Posts
2023 AMG GLE63s, 2017 AMG SL63, 2024 Sprinter, 1958 Chevrolet Corvette
93 vs 89 Octane
Am interested in any technical / testing data that may be out there. The GLS450 states 91 octane must be used. My favorite and convenient station carries 87 / 89 / 93. So, without having to "blend" every other fill-up, I am wondering if 89 is really detrimental, or is it simply marginally impactful on power and fuel mileage. Thanks,
The following users liked this post:
iridium18 (08-23-2017)
The following users liked this post:
iridium18 (08-23-2017)
#4
Junior Member
93 octane
From the instruction manual:
Only refuel using unleaded premium grade gasoline with at least 91 AKI/95 RON.
Given that 93 is at least 91, why not fill the entire tank with 93 and call it a day?
The following users liked this post:
iridium18 (08-23-2017)
#5
On the other hand, I rarely go over 2,500 RPMs, and almost never floor the accelerator. My understanding is that if you do not cause the high cylinder pressures of the turbo-boost at peak TQ, then you can get by with the lesser gasolines. On the other hand, if you attempt to get all the performance out of the 450 engine in the GLS maybe you should stick with 91 octane.
The following users liked this post:
iridium18 (08-23-2017)
#6
Junior Member
For someone who just paid over $80K for a truck, would saving $6 - $10 per gas tank be that important? Now, if it's a lease and you don't care about the truck, then it's a different story.
#7
Junior Member
I agree, whether a person can validate effects or not, the engineers that designed these trucks said we should use x octane, why not trust their knowledge?
The following users liked this post:
iridium18 (08-23-2017)
Trending Topics
#8
It is your car and you can put in it any gasoline that you want.
I listen to my car, and my engine is telling me that it is perfectly happy on mid-grade gasoline.
The following users liked this post:
iridium18 (08-23-2017)
#9
Junior Member
There is also a law in this country that any vehicle sold has to be able to at least limp home on the lowest octane available (87 ?) without damaging the engine.
It is your car and you can put in it any gasoline that you want.
I listen to my car, and my engine is telling me that it is perfectly happy on mid-grade gasoline.
It is your car and you can put in it any gasoline that you want.
I listen to my car, and my engine is telling me that it is perfectly happy on mid-grade gasoline.
I don't know the rating, however for my GLS550 I only used the high grade fuel from Costco as I feel they have a constant churn (look at the lines) and listed as top tier (likely just marketing).
I'm by no means an engineer, nor a mechanic. I trust the engineers to design a quality car, I also trust their judgement on the recommended fuel. I feel it's a rather cheap insurance to ensure top performance and longevity of my car's engine.
Love these forums, I now know about the limp home law and I'm sure there will be other things we all learn from each other.
The following users liked this post:
iridium18 (08-23-2017)
#10
Junior Member
Pretty sure my wife's gls had 87 octane when I picked it up today. Ran.....not great, loading up and stumbling 1,500-1,750rpm in 7/8/9th gears. Put in 50L of 94 three hours into the trip, then 47L 4 hours after. No more stumbling and it will kick down and hit the higher rpm range. It didn't want to before.
The following users liked this post:
iridium18 (08-23-2017)
#11
Here is an image from the dash on my GLS. We started in Oklahoma City and this image was taken a few miles before we arrived in St. Louis. As anyone can see, there are lots of miles (474), a pretty descent M/Hr (64) over 7+ hours of driving, and over 28 MPG. This probably represents the asymptotic limit to GLS gas consumption ?!?
The following users liked this post:
iridium18 (08-30-2017)
#12
Junior Member
Join Date: Aug 2017
Posts: 31
Received 0 Likes
on
0 Posts
2018 GLS450/2016 Range Rover Sport
Am interested in any technical / testing data that may be out there. The GLS450 states 91 octane must be used. My favorite and convenient station carries 87 / 89 / 93. So, without having to "blend" every other fill-up, I am wondering if 89 is really detrimental, or is it simply marginally impactful on power and fuel mileage. Thanks,
#13
Member
Am interested in any technical / testing data that may be out there. The GLS450 states 91 octane must be used. My favorite and convenient station carries 87 / 89 / 93. So, without having to "blend" every other fill-up, I am wondering if 89 is really detrimental, or is it simply marginally impactful on power and fuel mileage. Thanks,
#14
You cannot be serious. You are spending $80 grand on a car and you want to save a few nickels on gas??!! Seriously all luxury vehicles from Germany are built for 91+ octane. You will not damage the engine with lower octane but you will not get optimal engine performance and your savings will not be as high as you think as gas mileage will be worse. Switch stations or use the 93 octane. Seriously. Why buy the car if you don't want it to run at 100%.
B) can your GLS get the milage I am getting from mine? If not, then your argument has no merit!
C) My GLS is my truck, I don't need to get 100% of the performance it has out of it--that is what my Ferrari is for.
#15
Junior Member
Sams & Costco
Sams & costco premium is usually less then the street price for regular. Plus get a Sams club cc and save another 5%. Between 4 cars I figure I save over a $ 1000.00 a year with a $ 50.00 membership. Makes premium less painful...
#16
Junior Member
Here is an image from the dash on my GLS. We started in Oklahoma City and this image was taken a few miles before we arrived in St. Louis. As anyone can see, there are lots of miles (474), a pretty descent M/Hr (64) over 7+ hours of driving, and over 28 MPG. This probably represents the asymptotic limit to GLS gas consumption ?!?
#17
MBWorld Fanatic!
Whilst I cannot provide an answer for running our NA V8 GL450 on regular; its always purred puurfectly on 93...
What I can give advice on is how it drastically affected our 2.0T VW.....
It turned into a sluggish, rough riding, high idling, non-smooth machine....
Everything turned uncouth....as if it was struggling and recuperating from an alcohol infused bender...
When I feed it 93...it changes its entire demeanor to a rev happy, purring perfectly pouncing panther.......
So, If the GLI which VW says is a-okay to run our 87 yet really recommends 93....
imagine how it might affect your Bi-Turbo...3.0 V6......with definitely more stresses than a NA model...
Although i'm very guilty of 87 in a loaner.lol
What I can give advice on is how it drastically affected our 2.0T VW.....
It turned into a sluggish, rough riding, high idling, non-smooth machine....
Everything turned uncouth....as if it was struggling and recuperating from an alcohol infused bender...
When I feed it 93...it changes its entire demeanor to a rev happy, purring perfectly pouncing panther.......
So, If the GLI which VW says is a-okay to run our 87 yet really recommends 93....
imagine how it might affect your Bi-Turbo...3.0 V6......with definitely more stresses than a NA model...
Although i'm very guilty of 87 in a loaner.lol
#18
Super Member
Thread Starter
Join Date: Jul 2017
Location: Houston Texas
Posts: 530
Received 153 Likes
on
136 Posts
2023 AMG GLE63s, 2017 AMG SL63, 2024 Sprinter, 1958 Chevrolet Corvette
hey KOMBIFAN, hilarious share on the 87 vs 93 ... I have never heard of a VW referred to as a "pouncing panther" before ... lol
thanks, am sticking with 93 top tier on my '18 GLS
thanks, am sticking with 93 top tier on my '18 GLS
The following users liked this post:
kombifan (11-28-2017)
#20
MBWorld Fanatic!
Nice! Have you done a hand calculation yet to see how accurate the computer is? I don't have a GLS (yet), but all other MB's I've had always show about 1 to 2 mpg too optimistic on the computer estimate. Real life calculation (# miles driven / # gallons pumped) always comes out 1 to 2 mpg lower.
#22
MBWorld Fanatic!
A) one actually gets better milage with lower octane--lower octane gasolines have greater energy content. As long as the engine is not pinging and not suffering from detonation the engine has all the octant it needs.
B) can your GLS get the milage I am getting from mine? If not, then your argument has no merit!
C) My GLS is my truck, I don't need to get 100% of the performance it has out of it--that is what my Ferrari is for.
B) can your GLS get the milage I am getting from mine? If not, then your argument has no merit!
C) My GLS is my truck, I don't need to get 100% of the performance it has out of it--that is what my Ferrari is for.