I fully agree, they also put this in there
And then you contact your dealer, they fill it with 91 and say they can't reproduce it. Then you keep pestering them until foreman drives with you to confirm the issue, then they do TSB clean and fill it with 91 send you on your way. Then you talk to the foreman and he says he says the SOA tech told him the car should be filled with 91 to avoid pinging. So you contact SOA say it isn't fixed and they say to get a second opinion from another dealer. You show up with an appointment they make you wait 3 hours then the obese idiot won't sit in the car with you because he's scared of the coof and writes that he can't reproduce the issue and the muffler is probably the cause. Then you write scathing reviews and the GM contacts you and goes for a ride and confirms the issue issue to SOA. Then SOA goes into cover up mode and claims the dealer said there's no issue and closes the case. Then you email SOA but they ignore emails they don't like. Then you call SOA and they literally blocked your number never call you back have to use a different number open a new case they close it. Then you go to a different dealer they keep your car for 30+ days can't fix it in the end fill it with 91 and send you on your way. Then you contact that GM and ask if he really told SOA that your car was operating as intended, and he replies in writing that this is a lie and he told them it is broken.
I only use top tier fuel. I noticed the ping at like 2k miles when I began driving on a certain road which caused a ping. I mentioned it to a service tech and he just shrugged said its pinging and told me to use higher fuel. I knew little about cars at that time and didn't question further.It's been interesting reading all of this. We have had 3 Impreza Sedans since 2014 including the latest which is a 2019. We always use 87 octane gas and never heard any pinging. Subaru states the car is designed to run on 87 octane out from the factory so what might cause it ping? If it pings right when it was new that is an issue. It either means your fuel isn't really 87 or that something with timing is wrong.
If the engine starts to ping as time goes by this would indicate you are getting combustion build up in the cylinder which decreases the size of the chamber thereby increasing the compression ratio. The increased compression means you need higher octane fuel to prevent pre-ignition of the fuel before the spark fires. This will of course cost you more.
You can reduce or prevent combustion chamber build up by only using Top Tier rated gasoline. You can check online for which brand are actually Top Tier and if it doesn't hold the certification than it not. The fuel suppliers will have all sorts of fancy sounds names around their fuel like "Techron" but that is just a branding not a specification. Top Tier is a specific formulation of additives and a consortium of auto manufacturers and fuel suppliers created to improve the detergent characteristics of the gasoline. At any given brand you will find that all the fuel is or is not Top Tier, the octane rating has nothing to with it. TOP TIER - High-quality Fuel Performance Standard - TOP TIER™
You might wonder if this is all some kind of black magic hocus pocus to get you to pay more for gas. The American Automobile Associate wondered that and did some testing. They ran engines with and without Top Tier fuel and than took them apart. They found that after only 3000 miles the non-top tier engines were showing significant build up. The stuff works. Maybe its time for Subaru to become the second Japanese manufacturer to recognize the value of Top Tier fuel. There companies all recommend it: Audi, BMW, Ford, GM, Honda, Daimler Truck, Mercedes-Benz, Navistar, Stellantis,Toyota,VW
Top Tier Gasoline Worth the Extra Price, Study Shows - Consumer Reports
A study by AAA shows that Top Tier gasoline is worth the extra cost to consumers. Consumer Reports lists car brands that recommend Top Tier gasoline and gas stations where you can buy Top Tier gas.www.consumerreports.org
I just got this car last April, noticed the pinging at probably 7000 miles. I love this car it’s an amazingly fun vehicle but it just seems like it was designed for high octane gas, and then they slapped an 87 sticker on it.It's been interesting reading all of this. We have had 3 Impreza Sedans since 2014 including the latest which is a 2019. We always use 87 octane gas and never heard any pinging. Subaru states the car is designed to run on 87 octane out from the factory so what might cause it ping? If it pings right when it was new that is an issue. It either means your fuel isn't really 87 or that something with timing is wrong.
If the engine starts to ping as time goes by this would indicate you are getting combustion build up in the cylinder which decreases the size of the chamber thereby increasing the compression ratio. The increased compression means you need higher octane fuel to prevent pre-ignition of the fuel before the spark fires. This will of course cost you more.
You can reduce or prevent combustion chamber build up by only using Top Tier rated gasoline. You can check online for which brand are actually Top Tier and if it doesn't hold the certification than it not. The fuel suppliers will have all sorts of fancy sounds names around their fuel like "Techron" but that is just a branding not a specification. Top Tier is a specific formulation of additives and a consortium of auto manufacturers and fuel suppliers created to improve the detergent characteristics of the gasoline. At any given brand you will find that all the fuel is or is not Top Tier, the octane rating has nothing to with it. TOP TIER - High-quality Fuel Performance Standard - TOP TIER™
You might wonder if this is all some kind of black magic hocus pocus to get you to pay more for gas. The American Automobile Associate wondered that and did some testing. They ran engines with and without Top Tier fuel and than took them apart. They found that after only 3000 miles the non-top tier engines were showing significant build up. The stuff works. Maybe its time for Subaru to become the second Japanese manufacturer to recognize the value of Top Tier fuel. There companies all recommend it: Audi, BMW, Ford, GM, Honda, Daimler Truck, Mercedes-Benz, Navistar, Stellantis,Toyota,VW
Top Tier Gasoline Worth the Extra Price, Study Shows - Consumer Reports
A study by AAA shows that Top Tier gasoline is worth the extra cost to consumers. Consumer Reports lists car brands that recommend Top Tier gasoline and gas stations where you can buy Top Tier gas.
Also, the Impreza is meant to compete with the Civics, the Corollas and the Sentras. Requiring 91 octane or higher would be bad marketing strategy in that respect. I'm guessing that there is at least more than one Subaru engineer who was upset at this marketing decision. For the record, I support the engineers.
The car feels more responsive and perhaps accelerates quicker when going up onramps. But I can't say that this characteristic improves MPG any.
I wonder if the Honda and Toyota engines use direct & port injection as the BRZ and GT86 do, could bore & stroke also cause a difference in compression ratios?
I am late to the party, but hell yeah! Congrats! Tbh I don't quite remember the last convo on this stuff, but I do apologize if I laughed at this 😅
That's an interesting question. Not sure about the fuel injection specs on those cars. I'm sure some Internet research could provide the answers.
Curious as to what altitude you live at?
Yes, I use Exxon's premium fuel, most noticeable in town driving. I get 24. Highway I get 32, at 75' above sea level. Also no more issues with pinging.
Video, no, just pay attention to rattling under your hood (like someone shaking the ball in a paint can fast). Easier to hear when going up hill slow with your window down providing you have some sound reflections. (Like driving next to a highway divider or parked cars, or heavy foliage). Best to hear when you're alone (no other cars around drowning out slight sounds) if you haven't heard it
I know of Mazda has made some interesting innovations with compression ratios with running 87 with a turbo engine. Their direct injection cools the combustion chamber including carefully calculated timings with their Skyactive-g engine. In fact that's the only engine that I know can get 40MPG on 87 and not ping with a 14:1 compression. I think Toyota teamed up with them as well to enhance their stand point with high compressions. I'm not certain about Honda.
