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5W-20 Oil

I just purchased a new honda fit and was told by the dealer to use 5W-20 oil. I had never heard of that weight before and noticed on the web that it is thinner, provides better MPG and CAFE numbers, but can reduce engine life. However, I feel like Honda knows best. My other car is a 19 year old accord, so I like to keep my cars in good shape. Should I switch to 5W-30 or stick with the 5W-20?

5W-20 if you want to keep your warranty.
Don’t believe everything you read on the web. Where’s the proof that 5W-20 API SM oil reduces engine life? Honda and Ford at least believe that it increases life. It reduces the wear that occurs at engine startup. Engine startup is where most of the engine wear comes from. It seems like reducing that would be a good thing.

Just use what the owners manual (not the dealer, sometimes they’re wrong) says. The Accord and Fit may need different oil weights. Many modern engines are designed for 5w-20.

but can reduce engine life

That would only apply to engines not designed for it. For an modern engine designed for it using a heavier oil can reduce engine life.

In the real world, very very few engines die due to oil failure.  A fair number die due to lack of oil or lack of changing it etc, but not from the use of the wrong oil.  Most of those that do die due to oil failure have been using an oil other than one that meets the specifications of the car manufacturer as printed in the owner's manual.

Stick with the manual. BTW don’t rely on the dealer to inform you or even to know what is in the manual. Use the manual.

Use the oil specified in the owner’s manual of each car. I don’t know where the idea that 5w20 can “reduce engine life” came from, but I would not put too much faith in the source.

The Honda engineers know what they’re doing. Follow their recommendations.

What do you use in the 19 year old Accord? How many miles on it? I have an '89 and I am curious . . . I try to keep my cars in good shape also and use different weights in Summer vs. Winter in the Accord now at 490,000 miles. Rocketman

rocketman, you should tell us what you’re using that got you nearly half a million miles out of your Accord!

I use 10w40 in the Winter (October-March) and 20w50 Summer (April-September) . . . have done that for years . . . used to go strictly 10w40 . . . at about 250,000 I started to use 20w50 in the Summer. The brand varies . . . whatever meets specs and is on sale, but no crap oil . . . usually I use Castrol, Pennzoil, Mobil (not synthetic). I check the valve clearances about 25k, very little adjustment. The car starts every time . . . gets 30 mpg combined . . . and “uses” about 1/4 of a quart every oil change . . . every 3,000 miles. Rocketman

rocketman, it’s important to tell the posters WHERE YOU LIVE. The type of performance you have experienced is typical for well maintained cars used in a tropical or semi-tropical environment. Or cars stored indoors and using a block heater in the winter. Using 10W40 in Minnesota with many cold starts would quickly cause excessive engine wear.

As far as OP’s Fit is concerned, I would stick with the manual, but use a Synthetic 5W20. That way I would be sure of sufficient film strength in hot weather.

My son has a Mazda 3 which calls for 5W20, but he uses a 0W30 full synthetic oil which gives great year round protection.

All owners manuals that I have checked recommend oil based on a climate chart. And although there has been a shift to lower viscosities in recent years the change has not been sudden or drastic as far as I can tell.

Sorry . . you’re right Doc . . . I live in the Pennsylvania Pocono Mountains . . . we get cold, but never a lot of below zero days. The 20w50 is thick and heavy at start-up, but cranks pretty easily in the Summer for me, never a problem. So does the 10w40 in Winter. I always allow for a warm-up of 30-60 seconds, but this car has a carb, which farts a bit when cold. I also drive “like an old lady” for the first 5-6 miles . . . an old mechanic once told me to treat the moving parts like they were made of glass until sufficiently warmed-up. Seems to have worked, at least for me. Rocketman

The short answer is to use whatever is printed on the oil filler cap. If it says 5W-20, use 5W-20. If it reads 5W-30 use 5W-30.

If you want to look at all the viscosities that can be used in your car, check the owner’s manual. They often have more than one that is acceptable to use based on the ambient temperatures.

All of my recent cars (1999 and up) have only given one oil recommendation, with no climate chart. (I do recall the charts from older cars.)
It makes sense to do away with it. The maximum oil temperature is practically the same whether it is -10 out or +100. So if you pick an oil that can handle the coolest start up temp, and the hottest engine temp, that should be all you need.

Can’t argue with success! I live on Lake Wallenpaupack near you. I like 5W oils in winter to ease the stress on the starter. Started this when I noted how tough it was to crank my motorcycles in winter with 10W oils and switch to 5W made a big difference in the bikes cranking. Figured it would make it easier on the car’s starter and less draw on battery when it gets real cold.

If I ever get a car to 400,000 I’ll know it works as good as your system!

It’s commonly required in Hondas and is readily available. Use what the good book says. is a good primer on oils if you’d like some more info. 5W-30 has a bit more “viscosity modifiers” than 5W-20, so it’s resistance to flow is a bit more at higher temperatures, but I recommend against trying to second guess the designers.

I have an '88 Accord LXi with 218k miles in Wash. DC. These days I put 10w-30 in her year round.

Hmm, my cousin has a place on Wallenpaupack.

Howdy, feel better mersedes oil 00w .
The 5w verses 10 is good in winter if you live and drive where it is below 30* as it is thinner when cold start.
All this huba otherwise i have never heard of an enggine failure do to weight of oil when the oil chanaging every 3000 miles… How about you all?.

Someone posted here about a failure of an oil pump due to heavy oil in cold weather . . . gotta be careful with that. Rocketman