98 V70 Octane Level Suggestion

pmelan · Post by **pmelan** » 13 Nov 2009, 07:31

Good morning-

My 98 V70 has been running fairly well since its purchase in 2007. The problem I started to encounter is when I accelerate, the car seems to want to go but there seems to be something preventing the car from going faster, like an obstruction of some sort. I've tried my local dealer several times and last night I had an oil change scheduled and discussed the same problem with the service advisor. The tech took it for a ride and suggested the fuel filter assembly be replaced, just to see if that would work. I said fine so they went ahead and made the repair.

What I would like to ask is if using a higher octane fuel would help the car run more efficiently? A friend of mine recommended I put higher octane fuel once a month but with cost of gas being high, I tend to go with standard 87 octane.

Thanks in advance.

Peter

Post by **jblackburn** » 13 Nov 2009, 07:38

And the answer is yes! The knock sensors in your car will retard the timing and make the engine slower if it detects detonation caused by lower-grade fuel (and less fuel efficient as well). These engines were designed to run on 91 or higher octane. My Turbo HATES 87 octane gas - I made that mistake only once; I tend to go with 89 most of the time, but it boosts and accelerates much quicker when I splurge and go for the 93. MPG also increases with higher octane, so you're not really losing much $.

Post by **polskamafia mjl** » 13 Nov 2009, 11:34

pmelan, since you're in Easton you should have a Giant near you. Get a bonus card, buy some groceries and use the points to buy 89 or 91. Like jackblack said, these cars were designed to run on 91. It will hopefully help you out. Did the new fuel filter change anything?

Rich · Post by **Rich** » 13 Nov 2009, 12:29

I have recently found out the value of spending the extra for the higher octane gas. It has definatly made a differance with performance just in the daily commute.
I'd recomend it.
P.S.
There is nothing "cheap" about these cars lol! Not even the gas, but thats the price to pay to drive such a great car.

Post by **polskamafia mjl** » 13 Nov 2009, 12:38

True True. lol

volvomileage · Post by **volvomileage** » 13 Nov 2009, 16:24

in a non turbo engine i doubt its going to make a big change...does not in mine

in a turbo, then i would be more inclined to go for a higher octane..

id start with a good gas additive to clean injectors...

if you are getting a big performance change i would check the basic stuff plugs, cap rotor or any vaccum leak, and perhaps look at the maf to see if dirty or not...looking never hurt, the gas filter was a good idea if it has been a while it was there

my 2 cents..

pmelan · Post by **pmelan** » 14 Nov 2009, 08:21

Believe it or not, the fuel filter did make a difference. I wouldn't say it's 100% but it drives better and I have to agree that putting a higher octane gas into the engine should make a difference. Thanks for all your replies.

Post by **polskamafia mjl** » 14 Nov 2009, 21:02

Not a problem. As far as cleaning the injectors, I think jackblack suggested pouring seafoam into the gas tank.

Post by **charlyW** » 15 Nov 2009, 07:34

I normally stick in 95 ron fuel a touch higher than usa regular and if I'm really feeling flush [or just want to blast down the motorway] I'll stick in either super plus which has an octane of 98 somewhere close to usa premium or super

Post by **matthew1** » 15 Nov 2009, 14:01

Think about the price of mid- or high-grade fuel this way:

at $1/gallon, high-grade was around $1.15, or 15% more.
at $2.50/gallon, high-grade is $2.70, or only 8% more.

The more fuel costs, the cheaper it is -- relatively -- to upgrade octane.