nah, additive packages now last the life of the oil really. more frequent changes now are needed when the oil becomes contaminated with fuels or particulates.


i dont doubt he knows his stuff well, but dealers like to change oil often since it puts customers at ease. one of my teachers was also a GM tech, but he taught at their training center as well (gets his hands on all the new models). he told us that 3k miles is baloney unless ALL you do are short stop and go trips on a cold engine, just a few miles at operating temp will start to boil off the gasoline thats washed into the crank. he said that convention oils now (good ones) will do 5k change intervals for a commuter no problem, its the soccer moms you gotta watch out for.

>
well there you go. 99% of my driving is less than 5 miles. but it takes like 15 minutes to go those 5 miles. so my car usually reaches normal operating temperature for like 10 minutes. but it's still mostly stop and go.

ya, thats what he calls 'soccer mom' driving.

horrible gas mileage here. just idling i can notice the needle going down... Very very slowly but still. boosting it drinks gas. but its not my daily anymore so its all good in the hood.

>


>

You should see my oil at 2500miles [Granted I live in Houston where there is traffic at 9PM on a weekday]. I use Mobile1 fully synthetic 15w-50 with a Toyota filter and change it at 2500-3Kmiles everytime. The oil is thin and black and the engine feels so much smoother after the change.
Furthermore I'm a lubrication engineer for large engines and compressors in the oil and natural gas industry. Unless you make mostly long highway trips you're above info is just dead wrong. The worst of which is the bit about reusing your oil filter. You can starve your motor for oil on an older engine with higher milelage like that.

>
x2 I use mobil one synthetic 10w-30 and toyota filters. when I change my oil after 3K it's usually way way darker than the brand new stuff I put it.

and I use a new filter everytime. it's not like changing the oil is a hard or expensive job, and it's not like you hurt anything by changing it more often.

For those that are doubting me, read this forum here:

http://www.supramania.com/forums/forumdisplay.php?f=108

Very good info, you'll learn something.

-Matt

I'm not doubting you - we just obviously drive differently. I told you I am an Engineer at a lubrication system Manufacturer [Engineering Manager to be exact] and I'm fully aware of the benifits of synthetic oils [also the downsides] - that's why I use them religiously. But my oil is pretty broken down @ 3K miles and that's why I change it then. You do what works for you.
BTW - Check the viscosity , just with your fingers, the next time your odometer gets to 3K. Be sure to have some fresh oil to compare to. I think you will be able to feel the difference. For people who are fanatical about maintaining their engines like 6strings and I - thats reason enough to change out more often. And certainly never to reuse oil filters.
BTW2 - Just because they drive Supras doesn't make them experts on lubrication.

This post has been edited by Negative: Apr 26, 2007 - 4:28 PM

>

I hope that's K&N air filter only *shudder*. Their Oil filters are the only ones as bad as Frams. They're total crap.

>

Keep in mind, many factory recommended service intervals are just plain wrong sometimes.

Your change interval should take into consideration the following:
1) Your driving conditions. Sever driving (Stop & Go, Short-Trips, High Temp, Forced Induction, Racing, 4 Wheeling...) conditions will require more frequent changes.
2) The quality / type of your oil & filter.


>

Yes and No. Stop and go driving is more harsh because:
1) During idling, the engine oil pressure is at it's lowest. However, this isn't as big of a factor for most Toyota engines. Honda & Toyota engines run more volume / higher pressure oil pumps than other manufacturers, so even at idle the internal bits are well lubricated.

2) During acceleration, more gas is needed to get an engine moving, so there's a higher percentage of fuel/air ratio (I think yota's are 14.5:1) during acceleration. This extra gas bathes off more oil from the cylinder walls, and more fuel "seeps" into the oil system (which makes it go bad sooner). It's the latter we're concerned with when addressing change intervals. Newer formulations of oil (including conventional oil, but especially synth oil) are WAY WAY WAY better at handling extra fuel / moisture in them than the oils of old.

>

Oil analysis tests done after oil was pulled from an engine says otherwise. Trust whatever source you wish.
What is oil analysis
Several charts & graphs and other fun data sources


>

Do you have any data to support this? I ask because other engineers in the oil industry don't agree with you.
http://theoildrop.server101.com/forums/sho...ge=0#Post817161
http://theoildrop.server101.com/forums/pos...&Board=UBB6
http://www.autoeducation.com/autoshop101/oil-change-9.htm
http://www.amsoil.com/lit/lng_article/index.aspx
http://en.wikipedia.org/wiki/Motor_oil
http://theoildrop.server101.com/forums/sho...true#Post855942
http://theoildrop.server101.com/forums/pos...&Board=UBB3


Throwing out blanket statements without regard to build quality, formulations, or brands discredits your statements. It stands to reason (and there's tuns of oil analysis to back this up) good quality oils & filters will have longer service intervals than poor quality ones.

>

It's hard for me to take you seriously when you're using a crappy oil (Mobile 1 re-formulated a while back, and it sucks now), and anything higher than 10W-30.

>

It's completely clear to me you have no fundamental knowledge of how oil filters work. You're inferring to the oil filter getting too clogged to allow proper oil flow through the oil system. In the US, oil filter manufacturers are required by law to have bypass filters specifically to make sure the engine doesn't fail due to oil starvation.

The worst that can happen is that the filter will get clogged with contaminants, and the bypass filter will allow unfiltered oil to flow through the system. In the hundreds of oil filter tests I have read about, none - not a SINGLE oil filter (not even the HORRIBLE QUALITY ONES) had got so many contaminants in it that it was starving the engine, or even utilizing the bypass valve as long as the filter was changed before 10,000 miles. Amsoil EaO, Purolators and Wix (Also sold under Napa Gold label) are known to easily reach 15,000 miles and not be anywhere near clogging - even with guys who are 4 wheeling (which makes for some of the dirtiest oil).

That said, I change my oil filter at every oil change anyway 'cause I run a K&N air filter which dirties up the oil 2x faster than a paper filter

Negative: I never said that they were experts because they drive Supras. Look for a guy named "JDUB" on that forum, tell him what you told me and I bet he'd laugh at you.

Jeremiah: I'm talking about the air filter, trust me, I know K&N oil filters are crap. And thanks for bringing up factual info, a lot of people can talk but don't have facts to back it up.

-Matt

>


No problem. I'm not claiming to be an expert here - but I'll trust the people claiming to be experts, and who have data that's been repeatable from other non-biased sources to back up their claims and theories.

so lets compare gearing, my 4spd in the prizm at 60mph in OD with TCC on is running at just about 2100rpm. how about the 4spd or 5spd's in the celicas?

>
At 55mph I'm at about 2100-2200 RPM in 5th gear.

-Matt

This post has been edited by GotToyota: May 1, 2007 - 10:53 PM

I shift into 5th at 40 mph to cruise at 2000 rpms... 5th gear at 80 mph is 4000 rpms.

nice for accelleration, terrible for gas milage!

UPDATE! I just averaged 32MPG on my last tank of gas. 400 miles lasted me 3/4 of a tank (I fill up right around 1/4 tank left). I have a 5 speed, and shifted at 2500RPM in between every gear instead of the 3k like I used to do. I also went the speed limit, and was semi-light on the gas. Just wanted to let you guys know it is possible to get great gas mileage.

-Matt

This post has been edited by GotToyota: May 10, 2007 - 10:36 PM

I just filled up tonight and calculated it out to 21.17 MPG....

no idea...company pays for my gas...:lol:

I do mainly city driving (having to drive from school to school in the district) but sometimes I get on the freeway. I generally average 32-37MPG

>
Yes, but you're also an ST, I'm a GT.

-Matt

I do usually 120km/h on the highway and i can get from here to Toronto *430KM* on 3/4 of a tank..so i could probably get around 520KM to a tank...so i donno what that is as L/KM pr MPG

average city driving/some highway

very high 20's/low 30's depends how i drive

I'll get around 400 miles per fill up (running the tank bone dry)

I just skimmed this thread and am very surprised at the mileage many GT owners are getting.

I've owned my 94 GT since late 94. When I got it, it had 264 miles and had been hit hard in the front (dealer demo car). We repaired it & I've been driving it since.

I don't think in the 140,000 miles I've driven it, I've ever averaged less than 25mpg under any driving conditions (and the first 100K miles rarely saw a shift below 5000 RPM in the first few gears).

I typically get about 28 to 29mpg under my driving conditions which range from 50/50 city hwy to probably 20/80 city hwy. The vast majority of my fill ups are probably at around 28mpg. Rarely I get as low as 27 and I've seen as much as 30.

If these cars were equipped with another gear to get the RPMs down, I bet mid 30's on the road would be commonplace.

I typically get around 330 to 350 miles before filling up. I've had 400+ mile tanks rarely. Doesn't seem to matter much how I drive it - mileage will only vary a little.

This post has been edited by 86atc250r: May 24, 2007 - 11:21 AM

i get 300 miles out of 12.4 gallons , mixed freeway /city driving , not aggressive driving but i usually drive not less than 75 miles per hour on the freeway ... my car is a GT with auto tranny and i am avergin 24 MPG ( not good !)

Let me work this out... For comparrison:-

I filled my car the other day, cost £45.

Petrol/gas is £0.939 a Litre in UK at moment, so

45/0.939 = 47.9233 Litres bought.

UK Imperial Gallon is 4.54 Litres.

47.9233/4.54=10.555 Gallons

I get aroung 300 miles on a full tank too so

300/10.555 = 28.4225 Mpg Average.

I just bought a 94 GT and I do not care what the milage is because the car I am driving now gets between 6-8 mpg. Its a 1969 SS chevelle with an LT4 pushing out 425 rwh. Thats why I got the celica. Be happy with what you have because it could be worse.

I just got from a long highway trip, and got 675 KM on a tank, probably 700 if I were to run dry (7.8l/100 km,, 30 mpg)...I was impressed..I even took a picture hehe.


Just to say GT can have good gas mileage, even with a supposely drag inducting gt-four wing.

This post has been edited by Rayme: May 25, 2007 - 11:05 AM

Well I get average 450 miles between fill ups, thats filling to brim and its usually about 50 litres I put in. Thats a mixture of motorway and town driving, stick to speed limits going to work but "spirited"driving back Yo!

keith

This post has been edited by topshed: May 26, 2007 - 12:28 AM

sadly i get about 21 mpg. but thats w/ alot of "spritied driving" and too much idling. i think im running a little ritch too.

I get about 25 in city, but I have a soopa kick ass crack in my exaust manifold and lead foot. I usually cruise around 2500-3k rpms, usually 3k because I like to hop on it and go.

yeah i knoe what you mean. i did tht for awhile and dipped to 18 MPG
around 3K is where our engine wakes up/is most efficient