Newbie & Difinitive answer...

[medic]

I doubt there would be any difference in fuel economy because thy are both similar at operating temperature. The 5w would be advise due to the cooler ambient temp you guys see and the fact that 5w-xx oil pumps easier in these cooler temps.

The only differnce you may see between a 5w and a 10w would be at start-up.

 

[T-Keith]

I don't think you'll see a fuel economy gain, as others have said, but 5w30 would be a much better oil for Michigan weather, and it's the recomended oil for most vehicles.


What is a "pool vehicle maintenance garage"?

 

[Motoretro]

Hi guys, I'm new to the site and a new Toyota Tundra 4.7 owner. I also run a "pool" vehicle maintenance garage in which i'm attempting to put together a legitimate argument for going to 5w30 oil as our bulk supply of lubrication. Currently using Havoline 10w30 in over 150 vehicles in the fleet. Fleet consist of all brands of cars,vans,suvs and light duty trucks. We have never had a engine failure due to lubrication problems. Vehicles are retained for approximatley 70K before selling. Oil change intervals are at 5K with filter.
What i'm looking for is a difinitve number for the increase in gas mileage by changing to 5w30....any links out there pertaining to this? I need hard evidence since i will write this up as a company suggestion and the awards are based on percentage of money saved.
Thanks in advance,
Motoretro

 

[haley10]

Since Havoline 10w30 already has the API "Energy Conserving" Starburst, I doubt you can show any fuel economy improvements.

Sorry, but I don't think the case is there based on fuel economy.

The 10w30 "might" be the cheapest bulk deal and also show less consumption, to further negate any perceived fuel savings.

 

[drive it forever]

1st, havoline is a fine choice. 2nd, you should use the oil weight recommended by the auto maker(you should know that). 3rd, michigan, I think the 5w30 is more appropiate up there? 4th, I would offer mobil1 as a option to customers who are willing to pay for it. 5th beleive it or not, people will think more of valvoline then havoline because it has more name recognition (even though its less of an oil).I hope someone else replys about the 5 vs10w30 economy difference

 

[drive it forever]

I guess I read the topic of the post wrong.

 

[Motoretro]

Well, thanks guys for the input. There goes that 10k suggestion award.....Then again since the vehicles are parked outside and this winter has been especially cold, there may be an argument for a thinner oil. We've had a few non-starts on Monday mornings after sitting all weekend.

Mobil 1 would be a tough one. This would be a hard sell to management since their only interest is in saving money not spending more. Also these vehicles start out new and running the OCI up to a point that would be cost efficient using synthetics would void the drivetrain waranty.

T-Keith....Pool vehicle maintenance garage is where all maintenance is done to these vehicles.
The word Pool vehicle is just a old school phrase for fleet cars.

Motoretro

 

[Pablo]

No answer. Maybe = 0.

But yes - a 5W would be better in MI for cold starts.

You may study the time and money for oil changing vs. $ for a synthetic and extended drains.

 

[AEHaas]

This may help:
Effect of Break-In and Operating Conditions on Piston Ring and Cylinder Bore Wear in SI (Spark-Ignition) Engines, Schneider et al:
The rate of wear is much higher within 15-20 minutes of start-up than after reaching normal operating temperature. There was a lot of data but I conclude that the initial start-up time period (first 20 minutes) result is 100 nanometers of wear whereas the steady state wear rate was only 4 nanometers per hour thereafter. (Hence we should be concerned about start-up oil thickness more than running thickness. This justifies the statement that 95 percent of engine wear occurs just after start-up. Use an oil that is less viscous at star-up).

The Effects of Crankcase Oil Viscosity on Engine Friction at Low Temperatures, Cockbill et al:
By using lower viscosity oils there is less friction, improved cold weather starting, improved fuel economy, a savings of starting system components and less wear by increasing the rate of oil pressurization and flow in the upper oil galleries.

If you are using GF-3 oils now the GF-4 rated oils will have greater fuel economy, up to a percent. Using the latest SM rated oils should also be a benefit for fuel economy.

I agree with Pablo, study synthetic oils. They really maximize cool weather operation using something as a 0w30 oil.

aehaas

[ January 22, 2005, 09:58 AM: Message edited by: AEHaas ]