So I am in the process of purchasing a Volvo S80 T6 Executive. I didn't even think of this but realized it's a turbo, does it require a higher octane gas than standard? I don't have the manual with me so I can't look it up but what is the official rating for octane that should be used? Thanks.

It's a 2001, 97k miles.

 

91 is what you should be running in that

 

or 93 like here in florida

 

you dont have 91 in florida ?

 

91 or 93 is recommended, but will run on lower octane. See owners manual.

 

Our S80 2006 5 cylinder turbo runs fine on regular gas. Never , ever knocks.

 

I am pretty sure my 99's owners man says 87, but I have been running 89 with no issues. 87 just doens't seem right.

 

From Volvo's website:

I never use less then 91 though.

 

Andrei, all premium is 93 here in Fl. I think the only place that offers 91 is 7-11 but they offer about 5 or 6 grades...

I have never knocked using 87 but I do prefer the extra power of 93

 

So basically by employing a knock sensor (or two) this car can advance its timing to take advantage of higher octane levels and their resistance to knock.

Now on the T6 you dont want to be switching octanes often and going lower than 91 would not be recommended. I think that's bad because of the boost sensors ability to ramp up speed so quickly, think about it, the harder you push the car the more chance there is for engine knock, you dont want your knock sensor retarding your timing at a moment when you are pushing the car, it would throw off the boost sensor, i may be wrong but...

On the 2.9 its a bit easier on the engine, so im sure you can easily use 87 and not run into any problems, mind you that it is a higher compression ratio engine than the T6 (8:1 compared to 8:1 or so for the turbo)

i dunno, i only run 91 and have excellent torque and power response, fuel economy has been steady around 10.2 to 10.5 KM/L and for this heavy car, im not complaining

Id love to use 87 and save money, but i dont think its a good idea, maybe when i will know ill be getting rid of my car then ill switch without caring about it !!??!!

 

Hey guys,
M from Malaysia, m using ron95 and it works just fine :-)

 

So far been running '87 in the '02 t6 and nothing unusual, knocking/pinging or anything. The car is amazingly quiet, God knows with the oil prices the way they are '93 is out of the question. Would there be anything really to worry about by adding higher octane here and there?

 

No harm with adding higher octane on occasion, although I don't think, long term, it's smart to use 87 in a twin turbo car. I understand fuel prices are up, but relationally, the price from 87 to 91/93 is pretty much the same.

 

The problem with a semi-modern turbo car with knock sensors isnt detonation, but rather exhaust valve burn. Run 87 for long enough and you may run in to problems with this resulting ins a top end rebuild. Its one of those your mileage may vary things though, you never really know when its going to crop up. I like to punch it hard when I can, thats why I bought turbo cars so I run 91 or 93.

 

just got a 02 T6, running 87 seems fine, but I was wondering if running higher octane would give me better mpg, its about 18 (mostly city driving) right now

 

Oddly enough mine has gone from 17 to 19mpg average. The check engine light came on and two codes came up, one about the cats the other an o2 sensor. I think the cat (primary and secondary) are fine though. It came on and went off next time it was run. I'm not getting any bogging or loss of power so, just gonna play it by ear.

 

This is a two part issue one is the amount of detergents and the second is octane (knock).

Top-Tier Gasoline is a partnership of the auto manufactures and refiners which have agreed to use a proper amount of detergents (fuel system cleaners) in the gasoline that exceed the US standards which are too low. Shell, Chevron and Kwick Trip are a few examples of top-tier suppliers. Without the proper level of detergents (fuel system cleaners) in gasoline the entire fuel system, engine and exhaust system will have problems that will increase maintenance, repair, lower power, lower MPG or premature failure of systems like the ETM.

Octane is more complex, the higher the altitude (mountains) the lower the octane need of a gasoline engine but for most of us in the USA this is not an issue. For a T6 forced induction (Turbo) a higher octane is needed and should be used or knocking will be an issue as well as deposits (the system is reactive not proactive). For a non turbo the lower octane can be used.

If non top-tier gasoline is used buy the premium and frequently use fuel system cleaners like Techron (Chevron) or V-Power (Shell); there are many fine fuel additive packages available in addition to these. Basically you get what you pay for in cheap gasoline.

The American automakers use Chevron for EPA/MPG testing and European automakers use Shell.

Shell Premium is best for a T6.

This is a very quick and basic overview I have posted more in-depth explanations in the past.

 

As for the 91+ octane... I've alway wondered about that and recently seen a car TV show with some guy with a hot rod (old vett) explain that issue. The thing is that some cars with smaller motors design them to preform better by raising the compression ratio. If you use lower octaine gas in a car that runs compression over 9.0:1 it runs the risk of knocking. What the guy said was that a lot of car companies, mainly the ones that produce preformance cars, have high compression, some over 10.5:1.

What happens is the fuel injector sprays fuel in the chamber and the fuel is waiting for spark to create the explosion. Well, as the compression in the piston gets greater, lower octane gas has a lower flash point and may ignite before the spark is given. If this happens the chamber will get a premature ignition and cause the piston to receive the entergy before the spark gives it causing a knee jerk reaction that is called KNOCK (some men experience this with their lady friend, not good for that situation either). Now Volvo's have 2 knock sensors and do their best to avoid this situation/problem. The US Gov website advises people to knotch up the octane if they suspect or feel their motor is knocking, one level at a time. Volvos do a good job at preventing knock, however, if one of those knock sensors malfunction and your motor starts knocking, you can cause problems with your motor. I can't prove it, but I bet some people that are complaining about their car missing or running poorly have knock problem. The thing is that they would have to pump 91+ and run out the 87 to figure it out.

Now, I always thought that it was more important for a higher preformance motor to use 91+ octane, like the turbo since it put out more hp. Well, the fact of the matter is that the N/A motor is actually a higher compression motor, it has to be just to make it peppy with no turbo. If you look at the Volvo site, you will see that the specs of the motors are as follows when it comes to compression:

2.3 T3: Compression ratio 8.5:1
2.5 T: Compression ratio 9.0:1
2.5 NA: Compression ratio 10.5:1

https://www.customers.volvocars.com/..._133.htm#pg135

The 960 is even worse. It runs Compression ratio 10.7:1. I put some gas in the car one day and it would not drive over 45 mph until I ran down that gas.

Of all the cars, the T5 has the lowest compression.

Your car, you can do what you like. I do run 91+ mainly because the owerns manual recommends it and I think I get better mileage with it. You may not experience the knock with low octane gas unless you put your foot in it, not sure if there is any immediate price to pay but you will end up with burnt valves and maybe even worse, bent valves. I've also read about people compalining about their timing being off. I wonder if they are knocking. I also see a lot of people complaining about their car not wanting to rev above 4k. Makes me wonder if they put some octane boost in the tank will it make a difference.

 

i fill her up with midgrade octane