5W-40 Diesel Oil in a VTEC

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EvilShaddix

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This is my first posting. I have a 96 Crown Vic and Maxima. Both have 150K+ miles. I have been using Rotella T Synthetic(I know, just a fancy hydrocracked Group3 oil) for about 3 years now in both. I just added a 2002 Honda CR-V FWD to the mix. It has 100K miles. I would really like to keep to just using one oil in all my vehicles for the sake of simplicity's sake. I use the Rotella in both my lawn tractors as well. I see that the European oil recommended for VTEC Cr-V's is a 5W-40, supposedly due to the climate fluctuations across Europe. I have two questions for the incredibly astute and knowledgable group of BITOG members:
1. Will using 5W-40 Diesel spec.-oil adversly affect the operation of the VTEC system. For instance, being too thick to pump up properly into the uper valve train or too thick for the allegedly tight tolerances.
2. Is the lack of friction modifiers in Diesel oil that big a deal?
Thanks for the help.
 
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i believe the diesel oils are great oils, I run them in my bikes.

I believe the higher amounts of phos/zinc might eventually cause problems with the cat. But i dont think there is any solid proof of that, just speculation
 
I use diesel/universal formulations CI-4/SL in all of my gasoline engines except my CR-V. I use a 5W-30 Gasoline version in the Honda (mine is 2001, when they recommended 5W-30) The 5W-40 is much thicker (more viscous) than the recommended 5W-20, especially in some brands.

I have a couple of 5W-40's at the end of my paper on oil selection, although I was really looking to compare some to the 10W-30s recommended for Corvairs.
 
I don't think the thicker oil will hurt your VTEC. I'm currently running GC (German Castrol) in a 2004 Accord and it runs fine. The GC is a "heavy" 0w30 wt oil that runs close to a 40 wt oil when hot.

That being said, I think running a full up 40 wt like RTS in a Honda is a bit too thick. You'd be better off running a 30 wt.
 
Running a 40 weight in the CRV won't hurt anything, but it won't help anything either. Your gas mileage may slip a little and the car may even feel sluggish. My advice, stick to the Honda recommended 20 weight.
 
I would try it. I was told by several members on another forum that vtec wouldn't function when I went to a straight 30wt and it works fine.
 
Quote:
For instance, being too thick to pump up properly into the uper valve train or too thick for the allegedly tight tolerances.


..and would it not be the same for a 0W-20 in Alberta in the same car @ -25F? They survive "too thick" oil with their alleged tight clearances.

..and while we're here ..the same car that uses 5w or 0w-20 also uses it in the Texas panhandle ..and even in Alabama in 100F+ conditions.

Since the hot visc is not nearly as substantial as the cold visc differences ..and both cars in the respective regions under the respective conditions, one could reason that the use of any visc oil is not really a factor outside of those severe environments. That is, a 40 weight isn't of much concern to someone in cold situations for someone in Texas or Alabama and hot visc isn't a concern to someone in Alberta during the summer.

In short ..both see the other's detractors as "normal" under some condition at some point ..and survive to tell about it.

The major difference, for you, will be in short trip usage. You'll be pumping everything from "off the scale" ..all through 70 weight ..all the way down to 100C visc ..assuming that you reach 100C for the oil. Lighter oils give you a head start on this transition ..and end up a wee bit lighter at that temp.
 
I would not. I have a 2002 CRV and have run 5w30 PP in it and it seems sluggish and you will lose 3-4 mpg compared to the 5w20PP. What I have discovered is it really likes 50/50 5w30 & 5w20PP which is a 5w25. So I run 5w20 in winter and 5w25 in summer. No MPG loss with either. But a 40w is way to heavy IMO. You will be paying with fuel economy every time you turn the key.

Note: If you switch that engine to synthetic from dino you will get increased mechanical noise for about 2-3 OCI's Then it will subside to normal. If you do a 5w25 blend it will take 1 OCI. Don't ask me why.

Also: The trans service & diff service is way easy. I drain/fill the trans (3.5 qts Z-1) at 15,000 and the rear diff (1.1 qts dual pump) at 20,000. Make sure you use the dual pump fluid on the diff or it will start squealing on you and make you crazy.
 
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People on http://www.HondaSUV.com who have been using oils thicker than SAE30 have found out that VTEC solenoid stops functioning. Since the VTEC you have is iVTEC, it sends the engine into "limp mode" which would not let it rev past 2250 RPM (one of VTEC's switch over points). One guy took the solenoid apart, cleaned it and put it back. It worked. The 5W-40 maybe recommended for the iCTD (Honda diesel) engines, which we don't get here in the US, yet.
 
Originally Posted By: blueiedgod
People on http://www.HondaSUV.com who have been using oils thicker than SAE30 have found out that VTEC solenoid stops functioning.


So someone in Alberta ..on a dry road, cannot engage VTEC until about 15 miles of operation? That's when their 5w-20 is a 20 weight.

Help me reason this given that any oil can be any weight at a given temperature.
 
Originally Posted By: sprintman
I could put Penrite 40W70 in your VTEC and it would run fine. North Americans have 'viscosity phobia' and it shows. Get over it guys/gals.


Way too thick for a VTEC engine. Stick with the viscosity recommended by the manufacturer.

BTW. While higher viscosity oils have a place in older vehicles particularly in high temp areas, lower viscosity oils (5W-30, 0W-30, 5W-40) are being specified by most modern car manufacturers in Australia. Lexus in Australia specifies either a 5W-30, 10W-30, 15W-40 or 20W-50 oil for Australia based on ambient temps.

The North American climate (particularly Canada) is generally colder (on balance) than Australia so thinner oils are definately the go. Regardless an SAE 30 oil will work for both Australian and NA Summers
 
The point I was making is that it's almost impossible to say "you can't use a 5w-40 w/VTEC" without qualifications. It may be true that you may run into difficulties within the first 10 miles ..but otherwise, you HAVE to fall into some normal oil visc that every 20 and 30 weight ..either synth or conventional ... transitions through over a shorter number of miles. After 12-14 miles ..you SURELY have to be in the range that VTEC functions with 100% reliability.

Anything else has to be bunk.


Take a 100C visc of a 5w-40 ..let's call it 14.5CST. No one can tell me that VTEC won't work at that visc ..unless they also say that they wait for their 20 weight or 30 weight to also get to below 14.5CST ..which is WAY into oil warm up.
 
I agree with Gary on this one. Most of you are getting way too bend out of shape over viscosity issues here.

ANY oil is too thick on start ups, even in the heat of summer. MolaKule has said it, Bruce has said it, Pablo has probably said it, Dr. Haas I KNOW has said it. All oil to be in the required cST range has to be 100 C, as per the values given.

There are many posts on here with charts that good members have comprised to show just how thick a 0w20 is compared to a 20w50 at severly cold temperatures, yet are within points of each another as the temperature rises. The MAJOR benefit to thinner is start up wear in severe extremes, with the fuel mileage and coefficient of friction benefits tossed in.

It's amazing how much we here fret over so little...now if only other areas in the world's scheme of things we were that anal...
 
I did a web search and found that Honda of Malaysia sells a 5w-40 synthetic oil "specially formulated for VTEC engines". I just did achang with 5W-30. Malaysia is closer to the equator so I guess it never gets cold there. However, if Rotella is a 40W that acts like a 5W when cold, then how could this be? Are VTEC's sold in Malaysia that different from ours? Next oil change, I think I'll try my beloved Rotella 5W-40 and let y'all know how things go.
 
Originally Posted By: Gary Allan
Originally Posted By: blueiedgod
People on http://www.HondaSUV.com who have been using oils thicker than SAE30 have found out that VTEC solenoid stops functioning.


So someone in Alberta ..on a dry road, cannot engage VTEC until about 15 miles of operation? That's when their 5w-20 is a 20 weight.

Help me reason this given that any oil can be any weight at a given temperature.
grin2.gif
 
I'd use PP 5w-30 in them all. Also, for the trans service, maybe a few quick runs of plain Dex III ATF to rinse it out would be smart before putting in an expensive ATF. I settled on Castrol Hi-Mi ATF for my CRV. VI of 200!
 
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