Does Everyone put 91+ octane in your E Class?
Tulsa used to have 93 about 10 years ago.
"Being able to afford premium if you own a Benz" makes me chuckle. Do you know what kind of car Warren Buffet drives? Or the president of Ikea?
regarding whether 91 or 93 makes a difference, yes it does. I tune ecu's and going from 87 to 91 to 93 each has a substantial impact on how much timing the car can run (and not retard away from spark knock) and therefor how much throttle response and overall power it makes, not to mention fuel economy. of course, if the most advanced timing maps are tuned to 91, it won't do you any good to run 93. but if they are designed around 93 then you will be missing out using 91.
with that said, pump gas is so terrible and inconsistent that running a certain octane doesn't mean you will always be getting a quality 91....running 93 can help alleviate the effects of the odd tank and prevent the ecu from pulling timing. of course, running 110 octane race gas in a street car is much different. total waste.
Last edited by Higgs Boson; Mar 6, 2013 at 07:43 AM.
The ecu map can only tune down. So unless you have a tune you're wasting money buying 93. My last Benz had several standard levels of tune that could be accessed. I don't know if using 93 was one of them or not. The thinking on the levels of tune was if you were in a location that didn't have access to 91 you could still run at peak efficiency for what was available. During the gas crisis people were requesting a drop in tune to save money and they claimed they couldn't tell the difference when commuting.

FROM WIKIPEDIA:
Most fuel filling stations have two storage tanks (even those offering 3 or 4 octane levels): those motorists who purchase intermediate grade fuels are given a mixture of higher and lower octane fuels. "Premium" grade is fuel of higher octane, and the minimum grade sold is fuel of lower octane. Purchasing 91 octane fuel (where offered) simply means that more fuel of higher octane is blended with commensurately less fuel of lower octane, than when purchasing a lower grade. The detergents and other additives in the fuel are often, but not always, identical.
The Best of Mercedes & AMG
) all you needed to change your timing was a 3/8" wrench and a cheap timing light.A big Ford 460 V8 was set up to run on regular. However, if you were at high elevation like 5,000+ ft. (it's elevation for cars, not altitude) the car was really weak, a dud because it was gasping for oxygen, but you didn't know any better.
With premium gas, you could crank up the ignition advance a few notches BTDC and give the car a real kick in the butt (and improved gas mileage). It made a HUGE performance difference.
However, on a trip, if you were going downhill, so to speak, such as from Arizona downhill to Needles, CA, your car would start some serious pinging. You always had to have that wrench and timing light on a trip.
Last edited by Live Oak; Mar 6, 2013 at 02:46 PM.



Let's day you drive 10K per year and premium is 30 cents more, you *potentially* want to save $120 a year and risk damage to a car. If that is so, do you also pass on the recommended maintenance as well except for a quick oil change? You certainly will save more money there.
I wouldn't do it.
http://en.wikipedia.org/wiki/Octane_rating
Also, some gas stations in the US, particularly Sunoco, offer higher than 93, sometimes 101 octane, at their regular stations. Wouldn't make your E class any faster, but it's a nice option if you have a race car or high compression engine around.
I learned this in back in the day when I was putting 91 in my Mustang GT to "give it the best". Turned out I was wasting money to do worse for my car. The car even felt peppier with 87.
Do any of you run pure gas and if so, do you notice an improvement in mpg or performance?




Apparently, it costs more to refine premium, more to ship it via pipelines and distributors charge more to transport it in trucks. Anyway, that's their story.
Using less than 91 lowers your fuel efficiency and your performance.
BTW, can get non-ethanol premium in my area, but very expensive and only from indpendent stations.
I still run premium in my '98 190K A4 1.8T because that is what it was specified to run with.
Last edited by MBNUT1; Mar 10, 2013 at 02:18 PM.
) all you needed to change your timing was a 3/8" wrench and a cheap timing light.A big Ford 460 V8 was set up to run on regular. However, if you were at high elevation like 5,000+ ft. (it's elevation for cars, not altitude) the car was really weak, a dud because it was gasping for oxygen, but you didn't know any better.
With premium gas, you could crank up the ignition advance a few notches BTDC and give the car a real kick in the butt (and improved gas mileage). It made a HUGE performance difference.
However, on a trip, if you were going downhill, so to speak, such as from Arizona downhill to Needles, CA, your car would start some serious pinging. You always had to have that wrench and timing light on a trip.
I remember those days.....

Seems like one of those Aftermarket modules programmed for multiple types of driving (Sport, Economy, Valet, Factory stock/standard) would do the trick.







