2021 Civic. 8k Oil Change. Severe fuel dilution.

[twX]

with 91 roughly 20% more expensive than 87, it seems that you might almost make up the cost difference in efficiency/fuel economy.

That 15% extra fuel would only be at high engine loads, and only on an engine that is able to advance the timing a lot with higher octane fuel. At lower engine loads, ignition timing retard doesn't affect power and efficiency nearly as much, and if the load is low enough that knock isn't possible, there will be no timing retard at all.

So, in normal driving, I can't see fuel efficiency improving by more than a few percent with 91 vs 87, assuming the same ethanol content.

 

[himemsys]

That 15% extra fuel would only be at high engine loads, and only on an engine that is able to advance the timing a lot with higher octane fuel. At lower engine loads, ignition timing retard doesn't affect power and efficiency nearly as much, and if the load is low enough that knock isn't possible, there will be no timing retard at all.

So, in normal driving, I can't see fuel efficiency improving by more than a few percent with 91 vs 87, assuming the same ethanol content.

My point is, you will gain some of the cost back. It’s not a proportional loss to the cost difference between 87 and 91.

 

[Cherrybomb]

Just priced warranty through Hyannis Honda: 2024 CRV: 8 years, 120,000 miles, $100 deductible: $1,052. Seems reasonable. And as Honda’s actuaries are continuously crunching numbers it wouldn’t seem they see alarming reliability/durability trends with the 1.5T/CVT combination. Only exclusions are typical wear and tear items like upholstery, tires, batteries, wiper blades, etc. Good at any Honda dealer nation wide.

I passed on CRV in 2019 when I bought a new car.Honda had a known fuel dilution problem,but didn't seem to concerned.I'm looking again and that warranty makes it very attractive.My question is ,are required to do all services as recommended at Honda only shops?

 

[Danh]

I passed on CRV in 2019 when I bought a new car.Honda had a known fuel dilution problem,but didn't seem to concerned.I'm looking again and that warranty makes it very attractive.My question is ,are required to do all services as recommended at Honda only shops?

I think it’s like any OEM warranty: services have to be done on time and documented. Don’t think this precludes DIY or non-dealer service. Depending on your ownership time horizon I guess you could just follow the maintenance minder and have services at the dealer, even if you thought they were unrealistic.

 

[Speedy3861]

with 91 roughly 20% more expensive than 87, it seems that you might almost make up the cost difference in efficiency/fuel economy.

With my 2019 Civic Touring Coupe, I tried running Shell 93 for a 5000mi OCI. Things noted: MPG actually decreased slightly (computed) no difference in dilution (UOA's done every 5k) acceleration was slightly smoother and my gas bill was significantly higher. For whatever reason, this car had virtually no dilution issues, used Mobil1 0w20 AFE and Mobil1 M110a filters (from a stash I accumulated when they were made by Champion Labs) exclusively. My 2023 Civic dilution was 2.5% at 3000 miles, but the Mobil1 0w20 EP was still in grade. So now do OCI's at 3000-3500mi using Toptier 87.