What kind of gas mileage do you get? Options

[GotToyota]

I'd like to have an idea of what kind of gas mileage you guys get. I'll start:

Year/Model: 1995 GT
Transmission: 5 speed manual
Mods: Stock
Recent tune-ups/maintenance: New spark plugs, Gumout fuel treatment, filter and oil change, Seafoam treatment
Mileage: I just averaged 26 overall on my first tank of gas, this was with aggressive driving, and before the tune-up stuff mentioned above.

-Matt

This post has been edited by GotToyota: Apr 22, 2007 - 12:29 AM

[Jeremiah]

Can't wait to get a K&N replacement filter to see if the mileage goes up.

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.

toyota recommends 7500 under normal use and like 3750 under severe conditions.

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.

what most people don't seem to realize is, that just driving your car around the city or stop and go traffic (is there ever anything else in california?) are all considered severe conditions.

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.

he was a GM service technician for 10 years and has been teaching college level automotive classes for several years since.

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

Unless you make mostly long highway trips you're above info is just dead wrong.

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.

I use Mobile1 fully synthetic 15w-50

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.

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.

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