Vehicles that require premium gas

[LD1]

Any modern engine with a knock sensor will benefit from running higher octane gas.

Incorrect statement, again propagating the myth about high octane fuels

 

[Mikeeemo]

We just sold a 10 year old Acura that required premium fuel. It got 28 ~ 30 on premium and 19 on regular while knocking. So, if you don't need it, your wasting your money. Not all engine systems can adjust enough to stop the knocking.
Premium was not a big deal as we got the higher mileage & the price difference was small.
Fast forward 10 years, we have a Lexus that runs on regular, get the same or better mileage while delivering more power.

Stuff changes...

 

[zing]

LOL I have a supercharger on my pickup and the turbo is on our Subaru Forester. Neither one are exactly what you'd call a sports car. Forced induction is also a big benefit at altitude as you get sea level performace at altitude. I always compare it to adding a couple of extra cylinders to your engine. It makes a six banger perform like an eight and a four popper run like a six. I have the supercharger on the truck because I wanted added power and torque down low while a car usually does a little better with a turbo at higher RPM.

There are also safety factors involved in having enough power on tap to get yourself out of a situation too. Sure it costs me a little more at the pump but I'd rather have something happen when I mash the go pedal that being stuck like a deer in headlights when the crap hits the fan. IMHO all these econo boxes that can't pull a sick ***** out of bed or have enough power to get out of their own way are mostly just traffic hazards clogging our roadways.

Not sure what year yours is, but I also have the turbo charged Forester. 2009 model with a 2.5l four cylinder. Bought it used of lease with 30,000 kms on it as a daily driver for my wife and noticed that the computer was saying it got 10.2 l/100 km average. It says in the manual and on the gas fill cover that premium gas is required, but I said screw that, why pay more? Two years later it was getting 12.2 l/100 km and starting to drive sluggishly.I took it to my favorite garage and the mechanic commented that although everything was working as required, he noticed excessive carbon buildup. I switched to premium and now after a year the computer is showing 11.4 l/100 km, so it is gradually getting the economy back. Also feels less sluggish now. I am thinking now that I may start to treat the gas with seafoam and see if that also helps clean out some of the carbon.

For the OP, my experience is that if the car says it requires premium gas, you should use premium gas. The fuel economy savings may not necessarily equal the extra cost of fuel, but you also have to consider the impact on the engine over the long term and the impact of carbon buildup when your fuel is not burning the way it should.

 

[adventure bob]

"mechanic commented that although everything was working as required, he noticed excessive carbon buildup. I switched to premium..." This has absolutely nothing to do with the octane of the gas. It has everything to do with driving style and gas chosen with regard to added detergents. The higher end name brand gases, Shell, Chevron ect add better additive packages to their "premium" fuels for sales reasons. Those better additive packages are what keeps the carbon buildup low, not the octane level.

 

[dickfoster]

Not sure what year yours is, but I also have the turbo charged Forester. 2009 model with a 2.5l four cylinder. Bought it used of lease with 30,000 kms on it as a daily driver for my wife and noticed that the computer was saying it got 10.2 l/100 km average. It says in the manual and on the gas fill cover that premium gas is required, but I said screw that, why pay more? Two years later it was getting 12.2 l/100 km and starting to drive sluggishly.I took it to my favorite garage and the mechanic commented that although everything was working as required, he noticed excessive carbon buildup. I switched to premium and now after a year the computer is showing 11.4 l/100 km, so it is gradually getting the economy back. Also feels less sluggish now. I am thinking now that I may start to treat the gas with seafoam and see if that also helps clean out some of the carbon.

For the OP, my experience is that if the car says it requires premium gas, you should use premium gas. The fuel economy savings may not necessarily equal the extra cost of fuel, but you also have to consider the impact on the engine over the long term and the impact of carbon buildup when your fuel is not burning the way it should.

I think her's is a 2004. The reason to use premium fuel in a forced induction engine is to prevent knock and ping as the compression ends up being higher since you start off with more air fuel density in the cylinder on the intake and compression stroke. Same effect as running a higher compression engine.

If you want to clean things up you might want to give Cataclean a try. That's what I'm using before going in for my smog checks now. I used to use Greased Lightning as a pre smog fuel system cleaner but I can't find it where I live now so I switched to Cataclean. I've used Seafoam before but never noticed much of an effect except for a lot of smoke and you could do that with a little diesel fuel. Not too sure that making smoke is going to reduce carbon deposits so I chalked it up as likely snake oil.

 

[JCByrd24]

My step dad and brother both ran VW 4-cylinder turbos to over 200K running regular. My son still running one of them on regular almost to 240K, the other was totalled in a fender bender. I always ran premium in my Audi 3.0 V6 (NA) and in my BMW 3.0 straight-6 (also NA). I figure it cost me significantly less per month then a lot of other things I spend spending money on so I never have to question myself if something happens.

The Tiguan is likely under pretty high boost even if you don't realize it, but the engine likely will take care of itself and ****** timing or reduce boost when running regular. It seems based on the experiences above the fuel is not necessarily going to reduce longevity a measurable amount. Making short trips and never letting the engine warm up, and really babying an engine is much more likely to lead to carbon/sludge build up and early demise.

That being said, if you are used to fueling a truck, putting premium in a Tiguan should still be saving you money. Do it, and let that smooth VW engine run hard every once in a while, and it will be fun and last you a long time and you'll never have to question yourself.